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The Really, Definitely Completely Un-Authorized TBS

 

The Really, Definitely Completely Un-Authorized TBS

 

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#1 Fred W

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Posted 06 April 2010 - 04:45 PM

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7/6/2015 - It has been reported that reading all of the comments and discussion in the replies to this thread can be a bit confusing.  All of the information required to perform the RDCUA TBS procedure is contained in this first post, or at the procedure linked to immediately below.  This post has been updated to reflect the best working procedure for first and second gen FJRs. 

 

(note that the RDCUA TBS cannot be performed on 3rd Gen FJRs)

 

 

3/2013 - I have captured and compiled a complete html version of this procedure and am hosting t at my fjr.nerds web space for posterity here: The Really, Definitely, Completely Un-Authorized Throttle Body Sync (TBS)

 

 

 

Re-edited 10/2012
This version of the UnAuthorized TBS procedure is based on a premise; that the ideal throttle synchronization is when the throttle plates are aligned with each other and parallel.

After a large number of uses, this procedure has been found to be very effective. Nobody who has used this procedure has ever said that it made their bike run worse. Most people say that their bike ran smoother (less vibration at ~4k-5k rpm ranges.

You will see some discussion in other posts about alternate ways to adjust the throttle plates. Some folks believe that you need to rev the engine. Some think that you need to load the engine and rev it. None of these other methods have been shown to be any more effective than doing it the way detailed here. And this way is a lot easier to do.






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The Really Definitely Completely UnAuthorized Throttle Body Sync


I decided to start a new thread to document this procedure. Not because it is so much different than any of the other UA TBS procedures, but because there are so many Throttle Body Sync threads. I'm hoping that this procedure becomes the new standard non-standard. The concept for this TBS procedure came from a thread / discussion I had with a short duration forum member from Maine, Alekso last year. The idea was to make a procedure that wasn't so convoluted and difficult to follow and understand as the original Unauthorized sync procedure.

For those just tuning in, what's going on here is that the "official" throttle body sync procedure, the one called out in the Factory Service Manual (FSM) and specified as a "required" procedure at 4k mi. intervals (what?) is simply an adjustment of the air bypass screws at idle speed. These bypass screws have their primary effect on vacuum at idle speed, and have very little to do with how smoothly the engine runs at anything other than at idle or just above. As the throttle butterfly plates open, the tiny amount of air contributed to the total intake by the bypass circuit becomes increasingly less significant so that by the time you are at 3-4k rpm these screws are pretty insignificant. What is significant at larger throttle openings would be the relative angles of the throttle plates.

The problem is that the FSM doesn't specify a procedure for properly aligning the throttle plates. They just say that the plates are set at the factory and to leave em the hell alone... huh.gif Being gearhead dweebs, we know that to achieve the smoothest possible running engine it is our goal for each of the 4 cylinders to contribute the identical amount of power per stroke. With Electronic Fuel Injection and Electronic Ignitions, the likelihood of balanced fueling a nd perfect ignition timing is much better than in the days of carburetors and points of the past. So our best tuning opportunity is to try to balance the air intakes, which can be best measured by the intake vacuums.

Prior "Unauthorised" TBS procedures suggested that you just open the throttle while observing the vacuum gauges and make the mechanical adjustments to the throttle linkage quickly. Surely that will work, but at what rpm do we need to go before the air from those bypass screws is nullified? And how sadistic is it to continually rev your engine while making these fine adjustments? (hint - they aren't all that quick)

Enter the RDC (Really Definitely Completely) Un-Authorized TBS.

The concept here is pretty simple. To align the throttle plates and eliminate the air contribution from the air by-pass screws, we just close them all the way before starting. Yep... it's just that simple.

So, to prove the concept I documented my most recent RDC UA TBS using a new (to me) Gunson Carb-tune vacuum gauge that I picked up over the winter:


After propping the tank up out of the way, here are the important adjustment points
(note - your under tank could look this uncluttered after installing the WynPro PAIR Block-Off plates and removing all the PAIR crap):

100_1211.jpg

V1 thru V4 are the 4 standard vacuum take-off points for hooking your vacuum gauge of choice to.

1-2, 2-3, and 3-4 are the mechanical linkage adjustment screws to adjust the relative angles of each cylinder's throttle butterfly plate.

Before I began, I documented what I had for vacuum at idle:
IdleB4.jpg

Not bad. Notice that #1 is a bit low and #4 is a bit high. Now, without making any adjustment I then revved the engine to ~3-4k rpm and used my Vista Cruise to hold it long enough to snap a picture:

3krpmB4.jpg

Hello! What's that? Now cyl #1 is high and #4 is low!! This is not good. No, not good at all...
(well really these aren't all that bad, but you get the idea...)


Procedure:

Close down (lightly) all 4 of the Air Bypass screws:

100_1217.jpg

100_1218.jpg



Depending on how open they were before, your engine may not want to idle. You can either crank the idle adjustment (under the right side of the tank) or use your Vista Cruise to hold a reasonable idle, like I did.

Now that the air screws are out of the picture, you can adjust the throttle plate linkage screws (at idle, not while winding the piss out of your poor engine) and balance the vacuums with the throttle plates angles.

Important: Start by balancing cyl 2-3 since 1 and 4 are effected by that adjustment. The only tricky part is if 2-3 needs adjustment you can't get a screwdriver on the adjustment screw. So, take a guess, shut the engine off, and open the throttle enough to get at the screw head. Adjust it one way and then restart the bike to see if you guessed right.

Once 2-3 is good, the 1-2 and 3-4 adjustments can easily be made invivo. If you want to rev the engine to various RPMs to see how much things vary (or don't), knock yourself out (I did). In fact I was a bit nervous of running the engine in the garage for so long, even with water cooling.

When you are completely happy with the balance, I suggest shutting the engine down, and then dialing in ~ 1 turn CCW (open) into each air bypass screw. Restart the engine and adjust your idle to ~1100rpm.
Now recheck your vacuum gauge. Since the throttle plates are now aligned, if there is any mis-balance simply adjust the bypass screws until it is balanced at idle.

When I completed this procedure I had dead nutz balance at idle, and it varied very, very little at any throttle opening. I have not ridden the bike yet after adjusting. It may not amount to a hill of beans, but at least I now know that, unequivocally the throttle has been fully balanced and any vibration that remains is not being caused by an intake mis-balance.

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#2 03HiYoSilver

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Posted 06 April 2010 - 05:31 PM

Fred,

Nice TBS writeup and good work. I did something similar to this and it works very well and creates a balanced baseline. 

#3 FJRBluesman

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Posted 06 April 2010 - 06:03 PM

Thank you sir Fred. I've been waiting a long time for your UTBS post. wink.gif 

BTW - -They looked so close anyway, did it really matter??? Let us know how it test rides.

Thanks. yahoo.gif
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#4 SacramentoMike

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Posted 06 April 2010 - 06:03 PM


Depressing. Nice, clear, well-illustrated write up. Any idiot should be able to follow it and perform it flawlessly. I got completely confused. sad.gif 

Thank God for Roseville Yamaha.


 

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#5 FJRBluesman

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Posted 06 April 2010 - 06:07 PM

QUOTE (SacramentoMike @ Apr 6 2010, 06:03 PM) <{POST_SNAPBACK}>
Depressing. Nice, clear, well-illustrated write up. Any idiot should be able to follow it and perform it flawlessly. I got completely confused. sad.gif 

Thank God for Roseville Yamaha.
I don't believe RVY will do the UATBS.... 
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#6 road runner

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Posted 06 April 2010 - 06:10 PM

Fred

Very nice write up and pics. 

Maybe it can get pinned in bin of facts or similar, so others can benefit from it. rolleyes.gif 

This is the exact way I did mine last year, and it works great. Mine were also very close, but I made them right on. They were so close I don't know if it made any difference in how it runs, but at least I know it's perfect.
It's a much more real world sinc, because now it will be equal all the way threw the RPM's instead of just at idle.

And I need to get a hold of Dave for a set of those plates.

Art 
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#7 S76

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Posted 06 April 2010 - 08:22 PM

Nice method!

I'm going to try that. 
Bob
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#8 RenoJohn

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Posted 06 April 2010 - 09:58 PM

very good......

I like your thinking and I'll be doing that:

+ close off the air bypass on all cylinders
+ adjust the throttle plate linkage screws (per Un-Authorized methodology)
+ Open air bypass screws ~1turn
+ sync cylinders using air bypass screws

Me likes the Un-Authorized TBS

-----
Me's only thoughts/comments:

After opening the air bypass screws (~1turn per your instructions), I'm assuming we should use cylinder #2 #3 as the baseline to sync the others? This is what I've done in the past.
so my question: How confident are you in the ~1turn open? ....and do you suggest using cylinder #2 #3 as the baseline??


thanks for this write-up totally grooovy

un-sync'd in reno ...John 

#9 03HiYoSilver

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Posted 06 April 2010 - 10:14 PM

RJ,

I believe you meant cylinder #3(baseline) to be turned out 1 turn and then do the fine tuning with the other banks, at least this is what I did. 

#10 RenoJohn

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Posted 06 April 2010 - 10:25 PM

QUOTE (03HiYoSilver @ Apr 6 2010, 10:14 PM) <{POST_SNAPBACK}>
RJ,

I believe you meant cylinder #3(baseline) to be turned out 1 turn and then do the fine tuning with the other banks, at least this is what I did.
YES!! thanks, #3, #3 ....I was just testin' ya all's.

Thanks Mr. Silver. I corrected my post.
 

#11 C&C

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Posted 07 April 2010 - 02:17 AM

Should it be known or mentioned that your intake should be scrupulously clean and free from carbon (especially on the back of the throttle plates); don't known, just asking.

And picking 'nits' here, but when you say, "Once 2-3 is good, the 1-2 and 3-4 adjustments can easily be made invitro."; since the engine is back on, shouldn't that read "in vivo".

In any case, excellent write-up. 

#12 Constant Mesh

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Posted 07 April 2010 - 04:35 AM

I could be wrong but I don't believe the 3-4 adjustment is affected by the 2-3 adjustment.

The throttle cables connect directly to TB3 so all the action starts at TB3. On the earlier FJR's the idle position of TB3 is controlled by the adjustment knob throttle stop. On the later models the idle rpm is controlled by a separate air valve and the closed position of TB3 is not adjustable. 

#13 Fred W

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Posted 07 April 2010 - 04:59 AM

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Yes, I meant to say in vivo, you caught me!
Certainly not in a test tube. Duh. rolleyes.gif (edited out my fox paws). 


As to the arbitrary 1 turn out on (all 4) air screws before doing the final adjustment there are two general goals at that point: Since the vacuum was just balanced (via the throttle plates) we want to open all of the 4 screws the same amount, and we want the amount of additional air from these openings to put the idle speed somewhere in the middle of the idle adjustment screw's range.

In my case, I took note of the average amount I had to screw them in to reach lightly seated. My #1 was originally only open 1/2 turn and my #4 was open ~1 1/2 turns, so I figured I should shoot for the middle of that. It really shouldn't matter what you make that setting, so long as you make them all equal and then adjust from there. You could open all four screws to 1 1/2 turns if you wanted and then balance them all to #3. Since the engine requires the same amount of intake air to run at 1100 rpm, it would just mean that you may end up bumping down your idle speed adjustment screw compared to mine. 


Yeah, my starting vacuums were not very far off, even at higher rpms, so it may not result in a big effect on vibration/smoothness. But as RoadRunner mentions above, at least it is all adjusted now. Hopefully for the better. As was pointed out to me via PM, the ideal way to adjust the throttle plates angles would be under load conditions (on a dyno). Unfortunately most of us don't have that luxury. It would be pretty cool to put a bike that just had this adjustment on a dyno to find out how much difference their is under load. Any takers?


And CM, you are correct. The throttle cable actuates the #3 throttle plate directly so the 3-4 adjustment is not effected by the 2-3. The main reason to get the #2-3 balance right first is because that one is the biggest PITA. The screw head points back where you can't get a driver on it, so you have to keep shutting down, adjusting and re-starting the engine to check the adjustment. You could do the 3-4 first if you really wanted and it should stay adjusted as you adjust 2-3.

I don't think your throttle has to be scrupulously clean, you'll just be balancing out any effect that the dirt may make. You probably should have a good idea that your valve clearances are in spec or you'll be trying to balance that out and may not be so successful.

Also, I have a 1st gen which has the adjustable throttle stop for idle adjust. I don't know how a 2nd gen idle adjust works. If it is as you describe then that may have an effect on this procedure? unsure.gif

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#14 3dogs

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Posted 07 April 2010 - 05:44 AM

The TB Sync procedure (fifth post down) that I wrote calls for gently accelerating the engine up to 4k (not revving the piss out of the poor engine that was mentioned) to balance the throttle plates. There are several problems with syncing the throttle blades at idle as outlined in this thread.

When you ride down the Interstate at 70mph the throttle plates are not closed but open part way. Getting them in sync at idle doesn't mean that they are synced/balanced at part throttle (the vast majority of engine operation takes place at part throttle). Accelerating the engine to balance the individual cylinder air flow will be a closer simulation to actual riding conditions than operating the engine at idle with minimum air flow. In fact if you sync the cylinders at idle and then rev the engine you'll find that they are not in balance. I've tried this at idle and the "revving the piss out of the engine" produces a better sync or balance.

Also, when holding the throttle open with a Vista Cruise, or by hand, the cylinders will never seem in balance because there is no load on the engine. Ideally the best sync method would be to use a dyno. With the engine loaded and maintaining real road speed the throttle can be synced accurately under real riding conditions--If you don't have a dyno use the acceleration method and you can get close to the same results. Revving the engine to sync fuel delivery is a method that has been used for years (before EFI) on carburetors both on cars and motorcycles and still is practiced today on carbed and EFI fuel systems. 


 

#15 mferriter

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Posted 07 April 2010 - 05:55 AM

QUOTE (3dogs @ Apr 7 2010, 08:44 AM) <{POST_SNAPBACK}>
The TB Sync procedure (fifth post down) that I wrote calls for gently accelerating the engine up to 4k (not revving the piss out of the poor engine that was mentioned) to balance the throttle plates. There are several problems with syncing the throttle blades at idle as outlined in this thread.

When you ride down the Interstate at 70mph the throttle plates are not closed but open part way. Getting them in sync at idle doesn't mean that they are synced/balanced at part throttle (the vast majority of engine operation takes place at part throttle). Accelerating the engine to balance the individual cylinder air flow will be a closer simulation to actual riding conditions than operating the engine at idle with minimum air flow. In fact if you sync the cylinders at idle and then rev the engine you'll find that they are not in balance. I've tried this at idle and the "revving the piss out of the engine" produces a better sync or balance.

Also, when holding the throttle open with a Vista Cruise, or by hand, the cylinders will never seem in balance because there is no load on the engine. Ideally the best sync method would be to use a dyno. With the engine loaded and maintaining real road speed the throttle can be synced accurately under real riding conditions--If you don't have a dyno use the acceleration method and you can get close to the same results. Revving the engine to sync fuel delivery is a method that has been used for years (before EFI) on carburetors both on cars and motorcycles and still is practiced today on carbed and EFI fuel systems.


It would be more accurate to do the adjustment while riding down the interstate at 70 mph. Definitely need the throttle lock to free up both hands, though. 

#16 Fred W

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Posted 07 April 2010 - 06:30 AM

edited to remove doubts about the procedure in post #1 

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#17 road runner

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Posted 07 April 2010 - 10:09 AM

I say the best way would be to send the heads, header, intake, tb's, cats, mufflers, all out to get ported, polished and flow checked and corrected, then sync it on a dyno, and maybe it would be perfect all the time. crazy.gif Oh yeah don't forget to index the plugs, and timing reluctor wheel, and get the injectors flow checked. blink.gif
and don't forget the octane booster. 
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#18 snikr

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Posted 07 April 2010 - 10:19 AM

So Fred W, if I bring over my FJR you going to do this TBS for me?? Sounds like it might be the way to go.

Tom 

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#19 wheatonFJR

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Posted 07 April 2010 - 10:49 AM

Very nice information....

...however, I see the "before" pictures, but no "after" pictures. 

Is this one a 'dem "have faith in me" deals?

signed,
Doubting Thomas in wheaton biggrin.gif
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#20 Fred W

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Posted 07 April 2010 - 01:08 PM

Yeah, that's it. Trust me, Ha ha... 

Sorry Thomas, I didn't take any pictures of the balanced condition after. It looked just like the before's except the 4 were all the same height. Posted Image

Actually. my point in those pictures of the gauge was just to show how it showed one thing at idle speed and at 4k rpm it was different. If all I had done was balance the air screws per the FSM it could only have hurt the 4k reading (if anything). 

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Posted 07 April 2010 - 02:49 PM

On your tuner I assume that stronger vacuums will yield higher columns. Yet the columns are a bit taller for higher rpm operation. That's opposite of what I would expect.

On the earlier FJR's with the adjustable throttle stop it's probably better to have the air screws just barely opened. This ensures that the throttle valves will be opened a bit more at idle. When you are adjusting the individual throttle valves back and forth it's good to end up with a bit of space between each valve's tang and its stop set at the factory. It may be possible for a throttle valve's tang to bang into its stop before the #3 valve's tang hits the knob adjusted stop.

A butterfly valve is not a very good flow control valve particularly when it's opened more than a few degrees. So adjusting it at minimal openings should yield the most satisfying results.

I find that a good sync has a great effect on shifting. If the sync is off I'll notice it at the shifter long before I detect a noticeable increase in overall vibration. 

#22 Fred W

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Posted 07 April 2010 - 03:05 PM

QUOTE (Constant Mesh @ Apr 7 2010, 05:49 PM) <{POST_SNAPBACK}>
On your tuner I assume that stronger vacuums will yield higher columns. Yet the columns are a bit taller for higher rpm operation. That's opposite of what I would expect.


Yeah me too. Good observation. I wonder if I reversed the photos somehow. blink.gif 

QUOTE
On the earlier FJR's with the adjustable throttle stop it's probably better to have the air screws just barely opened. This ensures that the throttle valves will be opened a bit more at idle. When you are adjusting the individual throttle valves back and forth it's good to end up with a bit of space between each valve's tang and its stop set at the factory. It may be possible for a throttle valve's tang to bang into its stop before the #3 valve's tang hits the knob adjusted stop.


Another good observation. That would definitely be confuscating to anyone not watching out (or aware) of the possibility 

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#23 road runner

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Posted 07 April 2010 - 03:16 PM

I was being a smart ash in my last post, but seriously, I did try the method of revving and watching, and it takes much longer, and is a pain in the ash. With no load on the engine it can run away really quick, and you will find yourself revving your engine for hours trying to get it just right. Not saying it can't be done, but it is a PIA. 

By doing it the way Fred W mentioned you are checking the plates at partial opening. Because the air screws are turned in all the way the throttle is opened a little to keep the engine running. If I were to guess, I would say the plates are open about the same amount as cruising speed even though the engine is at 1000 RPM. If you want to check the sync at more throttle opening you can also back off the idle screw a few turns (this will take more air from it) and keep the idle at 1000 with a vist or similar. 

This is checking it at partial opening, which is where the engine spends most of it's time. So I think it is the way to go , but thats just me. And I think if you check it after by the rev technique it will be very close. 
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#24 dustyrains

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Posted 07 April 2010 - 11:04 PM

I wonder, do bikes with throttle by wire also need periodic TBS? 
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#25 Fred W

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Posted 09 April 2010 - 03:08 AM

edited to remove doubts about the procedure in post #1 

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#26 Patriot

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Posted 09 April 2010 - 03:19 AM

QUOTE (Fred W @ Apr 9 2010, 05:08 AM) <{POST_SNAPBACK}>
during a fit of age related insomnia,

ah yes...sigh dribble.gif 

this thread is really cool and in a good way, running what brain cells still fire in moi

carry on and thanx

Mike 
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#27 road runner

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Posted 09 April 2010 - 07:25 AM

Wow Fred,

That is a lot of bench racing, and all true, however I will agree to disagree. rolleyes.gif 

I think Yamaha sets the throttle bodies up on a flow bench, not knowing the flow variations of the engine. Also the flow variations between cylinders is very insignificant, and that is what they concentrate on when designing an engine. Granted it is a production engine so you could do a little better, but we are not looking to get that extra 2.5 HP over the other guy. If the variation was a lot then you would have to do sync on a dyno at RPM like mentioned earlier, and I don't believe that is necessary. 

Like I said earlier when doing TBS like you first said you are checking the throttle plates at an angle somewhat more than idle even though the engine is at 1000, because by closing the air screws you have to open the throttle to give it enough air to run. So say the plates angle is equal to, oh say 2000 RPM. If you want to check the sync at a larger plate opening then you can also back out the idle speed air screw, this will take more air away, and you would have to open the throttle more to keep engine at 1000 RPM, and maybe that plate angle would be something like while cruising at 3000 RPM, But I don't know for sure.

Maybe if we can see the diag screen while riding, check what the TPS angle is at say 4000 RPM, then check it again at sync time and see if it's close. If not then close the idle speed screw (by turning counter clockwise) and recheck.I'm thinking if the air screws are closed that the TP angle will be close to cruise speed, and that is where it spends most of the time. 

Granted all this I describe will account for the TP opening at higher RPM, but it will not account for the engine variations at 4000 RPM (which I think will be very close). So when your all done do a gentle roll on the throttle and see if it's close., but you may want to check it before you put the air screws back so your checking apples & apples.

I'm done splitting hairs

My .02

Art 
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#28 Fred W

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Posted 09 April 2010 - 07:35 AM

Hey Art,

Bench racing and hair splitting beats actually working most any time. Well, except for when it's time to pay the bills that is... wink.gif

I agree, the throttles are set on a flow bench, but doesn't that mean that they will be compensating for the manifold's flow characteristics? And that this will result in them not being perfectly parrallel? I honestly do not know.

But it makes me wonder, if that is not the case, then why bother having adjustable air bypass screws?



 

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#29 road runner

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Posted 09 April 2010 - 08:08 AM

Hey Fred

I'm not 100% sure of any of it either. But I would think the air screws are there so we have a way to fine tune the idle sync for each engine. There may be slight variations from one to another, so this will give a way to compensate. It is an extra bonus to have them. My brothers Huabusa didn't have air screws, it was synced using the throttle link screws. So if you sync it at RPM it may not be perfect at idle and vise versa. It's like in the boat world some outboards have adjustable idle mix screws and some are fixed. It is nice having the ability to adjust both at RPM and at idle so we can have the best of both worlds. 
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#30 S76

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Posted 09 April 2010 - 09:05 AM


Here is my twisted understanding:

I think your original posting is correct, exept for some words that I didn't even understand. (vivo?)

Except, when you sync the throttle plates at 4 or 5K you are not syncing the plates. You are matching the inidvidual intake runner's vacuum. And this is what you want to do. The vacuum in the runners is directly proportional to how efficiently that cylinder is firing. * (See footnote.) The throttle bodies and intake runners are pretty much all the same, but the airbox is the fly in the ointment here. That is why if you ever did the Barbarian mod you found the factory mixture settings at like 5, 18, 18, 22. The 5, is #1. The air has to make a sharp corner to get there. Less air less fuel. The 22
is #4, which is a much straighter shot, better airflow needs more fuel.

So you are correct to just sync the intake vacuum at speed. But this means the butterflys are not equal at idle, so you fix the idle with the idle air bypass screws. Now both are pretty good.

I do it a little different. I set all the idle screws one turn out and then set the throttles at speed. Then make minor adjustments to the idle screws last. Then go back and check it at speed again to see itf the minor air screw changes changed the speed adjustment. Couple times back and forth and you have it.

However, let me throw this one fly in the ointment. I did a sync on a gen I, setting the idle to about 12oo RPM's. The owner said no put it back to 1000. OK. I just turned the main idle screw to obtain the 1000 and then rechecked the sync. It was all off. I don't know why this happens but it did on more than one bike. So from then on I recheck the sync at the very end to make sure it is not FUBAR'D.

*Vacuum is a funny thing. I've messed with it to the point of confusion on several occasions. Any given engine will have x amount of vacuum at idle. If you rev it to 4 or 5 K the vacuum will be higher. Why? Yes, the throttles are open more and it would seem that would reduce the vacuum, but the thottles are only open a little bit more at speed, and the increased RPM causes the pistons to draw much harder than at idle, more than compensating for the increased throttle opening. 

On the other hand if you were driving at low RPM and opened the throttle wide open your vacuum would go to zero, or there about. That's easy to understand. 
Bob
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#31 Zorlac

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Posted 09 April 2010 - 11:08 AM

"and the increased RPM causes the pistons to draw much harder than at idle"

Nah, they can only suck 1298cc's total, just more often above idle. tongue.gif
It makes sense when you don't think about it.

#32 SacramentoMike

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Posted 09 April 2010 - 01:47 PM

QUOTE (Fred W @ Apr 9 2010, 03:08 AM) <{POST_SNAPBACK}>
". . . I'm modifying my position that the throttle plates should be adjusted at idle. I have edited my original post in this thread to that effect. I will do some further experiments with 3Dogs' procedure of throttle variation, and maybe try a few other things (like balancing at ~2k rpm?), but in the interim, you are on your own. You have been warned.

By the way, on a test ride after adjusting the throttle plates at idle, my bike didn't run horrible. In fact, the difference (on my bike) was very subtle if any. But I think there is a potential that it could become worse on some bikes by following my prior procedure.



I feel much better now about my earlier confusion. I'm still confused; I just feel better about it now. smile.gif


 

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#33 Fred W

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Posted 09 April 2010 - 02:53 PM

Thanks to the many folks that have contributed to the discussion thus far. Especially to roadrunner (whose professional expertise I value greatly), Jeff Ashe and 3dogs. 

I wrote this procedure up thinking that I had it all figured out, and as usual I was wrong. Maybe. Definitely maybe. 
Yeah, I'm 100% sure it's maybe. blink.gif 



My point is, even if I did have it right to begin with, so what?!? 

It's much better for folks to be actually thinking (you remember how to do that?) about what it is they are doing, or adjusting, or attempting to do, and consider the ramifications and consequences, rather than just blindly going out and following procedures from some knucklehead chump that says: Hey This is the next best thing since sliced bread. 



Yeah, that should be interpretted to be me, 
or it could be someone else
Definitely. 

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#34 road runner

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Posted 09 April 2010 - 07:50 PM

Like Fred W just said about thinking. Thanks to you all for getting me to think some more about it.
I was hung up on taking play out of the linkage and the throttle opening at speed, when the real factor is vacuum at speed. I forgot about restriction would have more effect at higher RPM.

So I agree syncing the vacuum with the throttle plates at speed would be more accurate. I don't know how much different it will be to doing it at 1000 RPM, but I'm sure it will be different. I have tried it and it is a PIA, because the engine will run away revving it with no load, plus you can't watch the tach and vacuum gage at the same time. I will try it again next time I check the sync, although I don't think it's important to try to do it at 4000 RPM, because it will run away. If I just role on the throttle until about 4000 RPM and watch the vacuum that should do it. I think this is what 3 Dogs said. 
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#35 Patriot

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Posted 09 April 2010 - 08:06 PM

QUOTE (road runner @ Apr 9 2010, 09:50 PM) <{POST_SNAPBACK}>
Like Fred W just said about thinking. Thanks to you all for getting me to think some more about it.
I was hung up on taking play out of the linkage and the throttle opening at speed, when the real factor is vacuum at speed. I forgot about restriction would have more effect at higher RPM.

So I agree syncing the vacuum with the throttle plates at speed would be more accurate. I don't know how much different it will be to doing it at 1000 RPM, but I'm sure it will be different. I have tried it and it is a PIA, because the engine will run away revving it with no load, plus you can't watch the tach and vacuum gage at the same time. I will try it again next time I check the sync, although I don't think it's important to try to do it at 4000 RPM, because it will run away. If I just role on the throttle until about 4000 RPM and watch the vacuum that should do it. I think this is what 3 Dogs said.

throttle lock ??? ... 
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#36 Fred W

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Posted 10 April 2010 - 06:36 AM

Yes. Rolling on the throttle and watching the gauge, making note of the balance, then going back to idle for a quick linkage adjustment is the essence of the 3dogs method.

Patriot, using a throttle lock to hold it at 4-5k rpm with no load on it seems like cruel and unusual engine punishment to me. unsure.gif
I guess it might help determine if your CCT is OK though... ohmy.gif 

(sorry tongue.gif )

 

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#37 08FJR4ME

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Posted 10 April 2010 - 07:23 AM

I might as well contribute to the confusion. blink.gif 

A) Has one thought about the throttle plates being out of sink on purpose? Maybe MaMA Yamaha wants them this way to alloy for uneven air box distribution.

cool.gif What's the pluses to doing this? Other than eliminating some vibes from the bike is it worth it? At WOT I got all I can handle and some.

I have seen an increase in brain cell growth recently though. biggrin.gif 

Thanks Fred,
Get some rest, eh!

Now if only I can get help with spelling and grammar. sad.gif 

Edit: Admin's, every time I do a b with parenthesis I get a cool smiley. What's Up? 

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#38 Fred W

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Posted 10 April 2010 - 08:41 AM

QUOTE (08FJR4ME @ Apr 10 2010, 10:23 AM) <{POST_SNAPBACK}>
I might as well contribute to the confusion. blink.gif 

A) Has one thought about the throttle plates being out of sink on purpose? Maybe MaMA Yamaha wants them this way to alloy for uneven air box distribution.

cool.gif What's the pluses to doing this? Other than eliminating some vibes from the bike is it worth it? At WOT I got all I can handle and some.

I have seen an increase in brain cell growth recently though. biggrin.gif 

Thanks Fred,
Get some rest, eh!

Now if only I can get help with spelling and grammar. sad.gif 

Edit: Admin's, every time I do a b with parenthesis I get a cool smiley. What's Up?




In answer to A ), I think that is the consensus we are now reaching (that my plate adjustment at idle isn't a great idea)

The answer to B ) is: Strictly in search of the ultimate turbine-like, vibration-free engine. 
It is unlikely to increase total power any appreciable amount. One could also argue that when/if the engine was in complete balance, and there is a minimum vibration then the engine will wear less. But that would be a stretch. It is also possible that a balanced intake would result in better fuel economy, but I don't think that effect would be great enough to measure.




If you look at the code for the cool smiley it is capital B followed immediately by a right parenthesis mark.
Lower case b won't work either: cool.gif

Trick is to put a space between the letter and the paren. wink.gif

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#39 RadioHowie

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Posted 10 April 2010 - 09:01 PM

QUOTE (Fred W @ Apr 10 2010, 09:36 AM) <{POST_SNAPBACK}>
Patriot, using a throttle lock to hold it at 4-5k rpm with no load on it seems like cruel and unusual engine punishment to me. unsure.gif


So, Fred, what's the difference to the motor, as if it knows, between running at 4k WITH load and 4k with NO load? 

You imply that some disaster is wating in the wings. If that was true, wouldn't there be also be a difference between 4k rpm in first gear as opposed to 4k in fifth? No load, or different load....what difference would it make?

Just curious to your reasoning.

 

#40 Fred W

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Posted 11 April 2010 - 06:44 AM

That's a really good question, Howie. 

Somewhere in the archived depths of my mind I recall being taught (in power mechanics classes) that unnecessary revving of an engine with no load on it is bad for the engine. But I cannot for the life of me come up with a solid reason behind that theory. Is it a fallacy? Just another mechanical urban legend?

Maybe one of the really smart guys on here will help bail me out on this point? 
 

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Posted 11 April 2010 - 08:03 AM

I think we're still waiting for help to bail you out -- I'm with RH in this.
The engine's soul doesn't care one whit about the revolutions it's commanded to perform. Modern 600s routinely operate in the mid-teens of thousands RPM.
I will say that revving the engine hard, under-no-load, briefly (which puts it under an acceleration load) is an effective way to warm one up quickly and cleanly. Listen to race mechanics in the paddock someday and you'll hear that technique used. 
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#42 08FJR4ME

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Posted 11 April 2010 - 09:58 AM

QUOTE (Fred W @ Apr 11 2010, 09:44 AM) <{POST_SNAPBACK}>
That's a really good question, Howie. 

Somewhere in the archived depths of my mind I recall being taught (in power mechanics classes) that unnecessary revving of an engine with no load on it is bad for the engine. But I cannot for the life of me come up with a solid reason behind that theory. Is it a fallacy? Just another mechanical urban legend?

Maybe one of the really smart guys on here will help bail me out on this point?



Naaaah, If that was the case there would be Hardlys fraggin everywhere. rolleyes.gif biggrin.gif biggrin.gif biggrin.gif

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#43 Fred W

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Posted 12 April 2010 - 06:33 AM

OK, so it appears that my fear of revving is totally unfounded. 
Rev away you yahoos!! yahoo.gif 



Under the heading of increased state of confusion, I have another development in this UA TBS saga to report from this weekend: 

Sunday morning I propped the tank again to do some more fiddling and diddling. My intent was to re-do the adjustments at a higher throttle opening as per the 3dogs' procedure, since it makes so much sense. Hooked up the gauge set and adjusted the 4 screws to exactly 1 turn open. 

As I rolled on the throttle I could not identify any un-synchronized areas that I wanted to adjust out. unsure.gif Ignoring what happens on throttle closure, just paying attention to what they do as the throttle is opened. Even when I held the rpms at ~3-4k for a second or two, the 4 cylinders were pretty damn well balanced. huh? unsure.gif I thought for sure I'd see a difference.

When I allowed the engine to idle there was a little misbalance on #1 and #4 (as compared to 2 & 3) , so I touched them up with the air screws (each ~ 1/4T CCW ) and then rechecked balance as I opened the throttle. The air screws had very little effect and actually improved the balance if anything. 

Buttoned everything up and then took off for a nice 3 hour Sunday ride with pillion. 

What is really interesting was that there was a tangible improvement in the amount of vibration. Not where I expected to feel it (idle to 4k rpm) but more so at highway speeds above 4k rpm. Where I used to have a little buzziness above 70 mph there is now an eerie lack of vibration at 75-85 mph. I had previously just considered that to be the "nature of the beast". 

So my conclusion at this point is, even though we are all apparently in agreement that the throttle plate alignment should be done at higher rpm, the throttle linkage adjustments that I made earlier in the week with the throttle screws closed and the engine at idle seems to have made a marked improvement on the TBS. 

I realize that this is only one data point, and therefore not conclusive, but you may want to try initially setting your throttle plates / linkage at idle with the air screws closed, then check and adjust as needed with the throttle open. 

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#44 BritFJR

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Posted 20 April 2010 - 04:20 PM

QUOTE (Fred W @ Apr 7 2010, 12:45 AM) <{POST_SNAPBACK}>
EDIT - Although the below procedure works as advertised, further discussion dictates that you should also check the throttle plate alignment by rolling on the throttle and observing the balance at 3k-4k rpm. 


This unauthorized TBS procedure was based on a flawed premise; that the ideal throttle synchronization is when the throttle plates are aligned and parrallel. Following this procedure will not mess up your bike too badly, but it may not result in the ultimate synchronization over the factory settings.

For further detail see post # below.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I decided to start a new thread to document this procedure. Not because it is so much different than any of the other UA TBS procedures, but because there are so many Throttle Body Sync threads. I'm hoping that this procedure becomes the new standard non-standard. The concept for this TBS procedure came from a thread / discussion I had with a short duration forum member from Maine, Alekso last year. The idea was to make a procedure that wasn't so convoluted and difficult to follow and understand as the original Unauthorized sync procedure. 

For those just tuning in, what's going on here is that the "official" throttle body sync procedure, the one called out in the Factory Service Manual (FSM) and specified as a "required" procedure at 4k mi. intervals (what?) is simply an adjustment of the air bypass screws at idle speed. These bypass screws have their primary effect on vacuum at idle speed, and have very little to do with how smoothly the engine runs at anything other than at idle or just above. As the throttle butterfly plates open, the tiny amount of air contributed to the total intake by the bypass circuit becomes increasingly less significant so that by the time you are at 3-4k rpm these screws are pretty insignificant. What is significant at larger throttle openings would be the relative angles of the throttle plates.

The problem is that the FSM doesn't specify a procedure for properly aligning the throttle plates. They just say that the plates are set at the factory and to leave em the hell alone... huh.gif Being gearhead dweebs, we know that to achieve the smoothest possible running engine it is our goal for each of the 4 cylinders to contribute the identical amount of power per stroke. With Electronic Fuel Injection and Electronic Ignitions, the likelihood of balanced fueling a nd perfect ignition timing is much better than in the days of carburetors and points of the past. So our best tuning opportunity is to try to balance the air intakes, which can be best measured by the intake vacuums.

Prior "Unauthorised" TBS procedures suggested that you just open the throttle while observing the vacuum gauges and make the mechanical adjustments to the throttle linkage quickly. Surely that will work, but at what rpm do we need to go before the air from those bypass screws is nullified? And how sadistic is it to continually rev your engine while making these fine adjustments? (hint - they aren't all that quick)

Enter the RDC (Really Definitely Completely) Un-Authorized TBS.

The concept here is pretty simple. To align the throttle plates and eliminate the air contribution from the air by-pass screws, we just close them all the way before starting. Yep... it's just that simple. 

So, to prove the concept I documented my most recent RDC UA TBS using a new (to me) Gunson Carb-tune vacuum gauge that I picked up over the winter:


After propping the tank up out of the way, here are the important adjustment points 
(note - your under tank could look this uncluttered after installing the WynPro PAIR Block-Off plates and removing all the PAIR crap):



V1 thru V4 are the 4 standard vacuum take-off points for hooking your vacuum gauge of choice to.

1-2, 2-3, and 3-4 are the mechanical linkage adjustment screws to adjust the relative angles of each cylinder's throttle butterfly plate.

Before I began, I documented what I had for vacuum at idle:


Not bad. Notice that #1 is a bit low and #4 is a bit high. Now, without making any adjustment I then revved the engine to ~3-4k rpm and used my Vista Cruise to hold it long enough to snap a picture:



Hello! What's that? Now cyl #1 is high and #4 is low!! This is not good. No, not good at all...
(well really these aren't all that bad, but you get the idea...)


Procedure:

Close down (lightly) all 4 of the Air Bypass screws:







Depending on how open they were before, your engine may not want to idle. You can either crank the idle adjustment (under the right side of the tank) or use your Vista Cruise to hold a reasonable idle, like I did.

Now that the air screws are out of the picture, you can adjust the throttle plate linkage screws (at idle, not while winding the piss out of your poor engine) and balance the vacuums with the throttle plates angles. 

Important: Start by balancing cyl 2-3 since 1 and 4 are effected by that adjustment. The only tricky part is if 2-3 needs adjustment you can't get a screwdriver on the adjustment screw. So, take a guess, shut the engine off, and open the throttle enough to get at the screw head. Adjust it one way and then restart the bike to see if you guessed right.

Once 2-3 is good, the 1-2 and 3-4 adjustments can easily be made invivo. If you want to rev the engine to various RPMs to see how much things vary (or don't), knock yourself out (I did). In fact I was a bit nervous of running the engine in the garage for so long, even with water cooling.

When you are completely happy with the balance, I suggest shutting the engine down, and then dialing in ~ 1 turn CCW (open) into each air bypass screw. Restart the engine and adjust your idle to ~1100rpm. 
Now recheck your vacuum gauge. Since the throttle plates are now aligned, if there is any mis-balance simply adjust the bypass screws until it is balanced at idle.

When I completed this procedure I had dead nutz balance at idle, and it varied very, very little at any throttle opening. I have not ridden the bike yet after adjusting. It may not amount to a hill of beans, but at least I now know that, unequivocally the throttle has been fully balanced and any vibration that remains is not being caused by an intake mis-balance.





Hi Fred W,

Having been doing the Throttle body adjustment now for the last 5 or 6 years I've never been really all that impressed with the throttle response even though at idle (1000rpm) it purrs. Blipping the throttle wasn't a smooth ramp up in RPM's but a bit lumpy instead. 

I agree that the the butterfly throttle plate is a mechanical adjustment regardless of load etc they all need to open together that's it - the rest is done by ECU and the plethora of engine, fuel and air sensors to deal with loads etc.
Having read all that's to read on the site about the Unofficial TBS and normal TBS etc I decided to try your method, this is what I did -

The throttle body sync had already been done a few days before as part of its service (new spark plugs, oil, filters etc). And the bike was running well (except for the acceleration being lumpy as usual). Engine was already warmed up 3bars.

1. Hooked up the Gunson vacuum gauge as normal for a TBS to the four take-off points.
2. Got a pen and paper and long flat blade screwdriver and wrote down the number of turns in I had to turn in (and lightly seat) for each of the 4 Air Bypass Screws.
My results were Cylinder 

(1) 1 & 3/4 turns 
(2) 1 & 1/2 turns
(3) 1 & 1/2 turns
(4) 2 & 1/4 turns (why was this the highest?)

3. Started the engine and had to hold the throttle open to maintain revs, decided to turn the engine idle screw (under the right side of the tank) to get an idle of 1000 rpm. I took a look at the vacuum gauge and saw number 1 was over 20mm Hg higher than 2 number 4 was over 30 mm Hg higher than 3, and 3&4 was 15mm Hg more than 1&2. Maybe this accounted for the idle air screw turns differences above (yes there are TB manufacture tolerances) and this seemed to answer what I was seeing on the Vac Gauge.

4. Located the Butterfly Throttle Plate adjustment screws (one for 1&2 another for 3&4 and a third to adjust 1&2 to 3&4).
Using cylinder 3 as the reference, cylinder 4 was adjusted to 3, then cylinder 1 was adjusted to 2 and finally the third screw to balanced 1&2 to 3&4. 
I had to switch of the engine a couple of time to open the throttle as the screw is only accessible with the throttle held open (it rotates round into view on the throttle cable linkage). During this procedure the idle screw was adjusted several times to maintain 1000rpm.

5. Finally switched the engine off and locktite'd the adjustment screws. 

6. With the flat blade screwdriver - opened the TB Air Screws on all Cylinders to 1 & 1/4 turns and started the engine, revs were lowered to 1000rpm and looking at the vacuum gauge all were exactly 250mm Hg. Revved the engine a few times and made only a gnats adjustment but was v happy with the balance.

I put it all back together and went out for a 1 1/2 hour ride - I couldn't believe the difference to the throttle response - why hadn't I done this earlier! Pulling from posted speed limits (30 and 40mph) up to the national speed limit (60 and 70) was effortless in 4th and 5th gear - no labouring just 'crisp' acceleration. Just revving the engine sounds so much smoother no lumps. I'd recommend this adjustment to everyone to be done when you do the TBS it's really easy. Thanks for your posts on this and the pictures as this adjustment is a winner!
 

#45 Fred W

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Posted 20 April 2010 - 04:28 PM

Thanks very much for your feedback. I guess this procedure is now 2 for 2! yahoo.gif

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#46 BkrK12

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Posted 26 April 2010 - 11:18 AM

Fred,

Another data point.

I decided to try this today. Heated up the engine, turned the bleed air screws in, used the throttlemeister to hold a good idle and started the bike. 2 and 3 were dead on, 1 and 4 were about 5mm higher. Not being one to leave well enough alone, I decided to have a whack. 

The only thing I can tell you is that with the tank in any position that would allow the engine to draw gasoline, I could not get to either the 1-2 or 3-4 screws to adjust them. There is so much more stuff on the Gen2s that you can barely see the screws, much less access them. Gave up after an hour. Moved the bleed screws back out, fine tuned the vacuum and reset the idle to 1100.

Fought the good fight, retreated with dignity. The bike runs just fine. But, it annoys me that I couldn't get this done. I'm sure it'll keep nagging at me until I come up wiyh some other idea to get at the adjustment screws.

Dan 

#47 Fred W

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Posted 26 April 2010 - 11:39 AM

Dan,

Maybe try a shorter screwdriver? unsure.gif 

Or is it that you just can't get the tank high enough? I know the restriction on my 1st gen tank propping is the length of the wire that runs to the bottom of the fuel pump. When I did my valve check I just unplugged the two tank connectors, but obviously powering the pump is kind of important for the TBS.

PS - love the new avatar. Looks like my boy, Petey!



 

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#48 RadioHowie

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Posted 26 April 2010 - 12:39 PM

That a Labratard Retriever??? 

#49 mferriter

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Posted 27 April 2010 - 05:43 AM

SO, is there any definitive data to show that TBS actually improves performance? No theoretical arguments, does anyone have numbers? 

#50 Fred W

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Posted 27 April 2010 - 05:54 AM

I've never even heard that a TBS was supposed to improve performance
It just reduces engine vibration a little. 

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#51 Blind Squirrel

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Posted 27 April 2010 - 12:11 PM

I have read this entire thread through twice now. I think I have the gist of it but I have a question. Since I have a throttle lock would it make sense to lock it in at 2k-4k RPMs to do the adjustment? 

- Scott (Chesapeake Va.)

 

#52 BkrK12

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Posted 27 April 2010 - 12:42 PM

Fred,

Took the expedient of completely removing the gas tank so I could see what was going on (as I then realized you had done - based on your pictures). I was able to figure out paths that I could thread a screw driver down to get at the screws. I was also able to figure out that you can't use a phillips head, which is what I tried yesterday. Put the tank back on and hooked it up and was able to get through the whole procedure, although the Gen2 is still a pain in the neck to get to the screws.

Only got a short ride, but the engine really seems to rev much smoother. Can't tell about vibes yet - need some fifth gear/4000rpm time to do that. It also seems to come up off idle much more smoothly. I would say, if you're going to do a TBS, you might as well do it this way. I think the results are superior and, after you've done it a few times and gotten use to the procedure, it'll probably only take 10 minutes longer.

Thanks for writing this up.

Dan

P.S. I bet having the PAIR system in place will make it a much bigger PIA.
P.P.S. His name is Wilson and he's 11 months old. 

#53 Fred W

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Posted 27 April 2010 - 02:43 PM

QUOTE (Blind Squirrel @ Apr 27 2010, 03:11 PM) <{POST_SNAPBACK}>
I have read this entire thread through twice now. I think I have the gist of it but I have a question. Since I have a throttle lock would it make sense to lock it in at 2k-4k RPMs to do the adjustment?


You could, but I wouldn't.

It seems that if you close off all the air screws and adjust the throttle plates you get things very close to perfect. Then you can just watch the gauge as you roll on the throttle, or briefly hold it at various rpms, and decide if you want to make any changes.

The problem with trying to set your throttle lock at 4k rpm is it doesn't want to stay there. Someplace just north of 3k rpm it gets into a runaway condition when the engine is unloaded where it wants to rev to the limit. 

The more I do this the more it seems to fall into the "art" category (vs science) 

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#54 Patriot

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Posted 27 April 2010 - 03:02 PM

QUOTE (Fred W @ Apr 27 2010, 04:43 PM) <{POST_SNAPBACK}>
The more I do this the more it seems to fall into the "art" category

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#55 BritFJR

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Posted 27 April 2010 - 03:41 PM

I would say, if you're going to do a TBS, you might as well do it this way. I think the results are superior and, after you've done it a few times and gotten use to the procedure, it'll probably only take 10 minutes longer.


I would agree, having done the servicing and TBS for six years (had bike since new for 8 years - dealer serviced while in warranty) this adjustment has made the engine much much smoother in the rev range.

Since doing this adjustment the acceleration is very smooth and one other thing I've noticed is putting it into 4th gear in a 30mph limit at 2000rpm is smooth and it wants to pull whereas in the past it used to surge and going down to 3rd gear at 2500rpm was the only option.

I've done around 800 miles since adj and my fuel consumption is better at around 50mpg was 43mpg on average. Regarding the vibes I haven't noticed any difference to the vibes felt at the bars at 4-4500rpm.

I am definitely going to be incorporating this as part of the TBS in future. Well done FredW!!!

David 

#56 road runner

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Posted 27 April 2010 - 05:07 PM

QUOTE (Patriot @ Apr 27 2010, 06:02 PM) <{POST_SNAPBACK}>
QUOTE (Fred W @ Apr 27 2010, 04:43 PM) <{POST_SNAPBACK}>
[The more I do this the more it seems to fall into the "art" category


resemble resent that remark. confusedsmiley.png 

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#57 serhan

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Posted 08 May 2010 - 07:58 AM

Thanks for the info, I will try to do this as soon as my manometer arrives. I will also replace the spark plugs when I get in there.

Do car engines require this too? if not, why not?


Thanks. 
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#58 Fred W

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Posted 08 May 2010 - 01:44 PM

QUOTE (serhan @ May 8 2010, 10:58 AM) <{POST_SNAPBACK}>
Do car engines require this too? if not, why not?


Most automobile engines do not have individually adjustable throttle plates (or air bypass screws) for each cylinder. Even those with individual injectors typically have a single throttle body / throttle plate. Why they are designed differently is a very good (not great*) question. The design engineers must somehow be able to design out any variation in intake flow in the auto engine manifolds, but either can not or do not on the bike engines. Of course typical bike engine rpms are also somewhat higher than typical car engine rpms, so that may factor into it. unsure.gif 





* a great question is one that I know the answer to! wink.gif

 

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#59 Blind Squirrel

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Posted 21 May 2010 - 05:43 PM

Help!

I did the TBS after I got home this evening. I got everything running smoothly at ~4K with the air bypass screws closed. Next I turned all of the screws 1 turn. Working off of #3 as the base line I was able to get all cyls even. Everything was good.... except my idle is at 1300 RPM and I can't get it lower dribble.gif Is there an idle screw that I can adjust to bring the idle down, or am I going to have to try to readjust everything?

*Edit*

Got it! Found it on FJRTech.com! http://www.fjrtech.c...tem.cfm?item=28

- Scott (Chesapeake Va.)

 

#60 Blind Squirrel

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Posted 22 May 2010 - 08:39 AM

I took the bike out for a short spin this morning to test the results of my UA TBS attempt. I can sum it up in one word: WOW!!! yahoo.gif 

It is SO much smoother now. Before I had jerkiness in 1st and 2nd gear. It is gone. I had a slight vibration at 70 MPH (~ 4K). It is mostly gone. I got everything "close" before. I am going to do the UA TBS again and dial it all the way in.

Thanks to everyone that contributed to this thread!

I am now the proud owner of a Carbtune Pro. If there is anyone in the Hampton Roads/Tidewater area (or that is willing to ride to Chesapeake) that wants to use the Carbtune is welcome. Shoot me a PM and I will give you my contact info. We can do it here at my place, or you can borrow the Carbtune for a day to do it at your place. 

- Scott (Chesapeake Va.)

 

 

 

jsd

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Posted 31 May 2010 - 01:22 PM

I am new to the forum, and the bike. The vibrations have been getting steadily worse with milage, This sync not only removed the extra vibrations but smoothed out throttle response from idle. By the way my air screws were only out 1/4 turn from factory. 2200 miles. Thanks for the info ! 

#62 serhan

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Posted 01 June 2010 - 04:18 PM

Thanks for the post.

I tried normal TBS and it seems to smoothen it out, until 3300 rpm. Then I did the UTBS, and buzzing is now beyond 4K. 

One question I have is, do you use loctite on the bypass screws after you set them to their optimal positions?


Thanks,
S.

 
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#63 03HiYoSilver

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Posted 01 June 2010 - 05:05 PM

Serhan,

Instead of using LocTite, I use just a small dot of Colored Nail Polish at the edge of 1/4 of the Screw. 

#64 Fred W

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Posted 02 June 2010 - 04:35 AM

I've never used anything (loctite or nail polish) I doubt that they actually move at all between TBS'es. 

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#65 HawkWing

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Posted 27 September 2011 - 05:27 PM

Did the RDCUA TBS this weekend, in conjunction with Barbarian Jumper mod, on my '08. The synch wasn't off by much- the worst TB was around 15 mm off; the others all needed smaller adjustments. After setting at idle, one TB needed slight adjustment at higher RPM. Used throttlemeister to hold idle at 1000 while adjusting. Wow! The difference is absolutely worth the effort! I thought the bike ran smoothly before these adjustments, but now I know what SMOOTH is! These 2 mods greatly improved smoothness from idle to at least 6000 rpm (haven't had it higher yet). Improved throttle response- feels like there's more torque at low rpm. Taking off from idle much better. Not sure about gas mileage yet; was getting 44.0 before these mods, and after one-half tankful I'm showing 44.5 mpg avg. And I have been "gettin' on it" a bit; just enjoying the improved ride. One minor recommendation I'd make to those doing this procedure: before you adjust anything, observe synch at idle as well as accelerating through higher rpms. In my case, a small change made a big difference. Thanks to all who made this happen. :clapping:

#66 canadianfjrowner

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Posted 03 July 2012 - 12:24 PM

First of all, sorry to bring up an old thread, but I couldn't find an answer to my question in later threads. 

There was talk about calibrating the throttle plates at 4ooo rpm and the engine running away at that rpm. Somebody said it would be great to do this on a dyno as it would create real world torque on the motor. 

Now I thought, If you put the bike on the centre stand, put in 5th. gear and rev. the bike to, let's say 60 mph, and load it up by applying the rear brake, it would be just like being on a dyno. At this time, as you apply more brake pressure, you give more gas. This would be the most accurate way to set the butterflies. Of course, you have to dis-engage the ABS system by unplugging on of the speed sensors. This wouldn't hurt the brakes, as long as you don't do this all day long. In normal operation, hauling the bike down from 70 to 0 in a panic stop will put more strain on the brakes than this method for sure. 

I'm going to try this, but I need to buy a vacuum set for 4 carbs since I don't know anyone that has one.

Any feedback on my theory would be appreciated. 

#67 mcatrophy

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Posted 03 July 2012 - 02:46 PM

... Of course, you have to dis-engage the ABS system by unplugging on of the speed sensors. ...

No you don't. The ABS light will shout at you, but it won't stop the bike running.
Just watch out for overheating that rear brake. 

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#68 Blind Squirrel

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Posted 03 July 2012 - 03:07 PM

First of all, sorry to bring up an old thread, but I couldn't find an answer to my question in later threads. 

There was talk about calibrating the throttle plates at 4ooo rpm and the engine running away at that rpm. Somebody said it would be great to do this on a dyno as it would create real world torque on the motor. 

Now I thought, If you put the bike on the centre stand, put in 5th. gear and rev. the bike to, let's say 60 mph, and load it up by applying the rear brake, it would be just like being on a dyno. At this time, as you apply more brake pressure, you give more gas. This would be the most accurate way to set the butterflies. Of course, you have to dis-engage the ABS system by unplugging on of the speed sensors. This wouldn't hurt the brakes, as long as you don't do this all day long. In normal operation, hauling the bike down from 70 to 0 in a panic stop will put more strain on the brakes than this method for sure. 

I'm going to try this, but I need to buy a vacuum set for 4 carbs since I don't know anyone that has one.

Any feedback on my theory would be appreciated.



I can see it now... You lean on the back of the bike enough to make the rear tire touch the pavement and ZOOOOOOM!!! Off it will go without you!
Please make sure to video it so I can laugh my ass off at you! 

- Scott (Chesapeake Va.)

 

#69 Fred W

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Posted 03 July 2012 - 03:48 PM

There is apparently no reason to do all of that. The original procedure (adjusting the plates at idle with the air screws all closed) has worked for every person that has tried it. The 4000 rpm stuff is unnecessary. I wouldn't abuse my bike by trying to rev it to 4000 rpm and hold the rear brake on at the same time. The likelihood that you will be able to do that and also adjust the plates is pretty remote.

But if you do try it, do be sure to capture the event on video. :P

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#70 canadianfjrowner

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Posted 03 July 2012 - 05:42 PM

There is apparently no reason to do all of that. The original procedure (adjusting the plates at idle with the air screws all closed) has worked for every person that has tried it. The 4000 rpm stuff is unnecessary. I wouldn't abuse my bike by trying to rev it to 4000 rpm and hold the rear brake on at the same time. The likelihood that you will be able to do that and also adjust the plates is pretty remote.

But if you do try it, do be sure to capture the event on video. :P


I would take the measurement, then shut it down, then adjust and re-try. As long as no-one has done it, I don't mind being first. As for safety, than is easy to overcome with some common sense. Just proper secure the front tire down so it won't lift and be prepared for centrifical forces. I'll let you know the results. If it goes bad, trust me there will be no pictures. 

#71 Blind Squirrel

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Posted 04 July 2012 - 03:40 AM

If it goes bad, trust me there will be no pictures.


<_< You're no fun. ;)

- Scott (Chesapeake Va.)

 

#72 SCB

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Posted 06 July 2012 - 05:31 AM

I think I'm with Canadian on this. As I read the thread and guys suggested using a dyno my first thought was to put it in gear and use the rear brake. I guess I would do the procedure the way Fred et al lay it out and then, with the manometer still hooked up, put it in gear, load up the engine and see what happens. I don't think you'd have to hold it there for more than a few seconds to see if it holds the balance. Not sure what I would do with that new found info but I think it would be interesting. 

#73 stevet

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Posted 08 July 2012 - 07:09 PM

Now I thought, If you put the bike on the centre stand, put in 5th. gear and rev. the bike to, let's say 60 mph, and load it up by applying the rear brake, it would be just like being on a dyno. At this time, as you apply more brake pressure, you give more gas. This would be the most accurate way to set the butterflies. Of course, you have to dis-engage the ABS system by unplugging on of the speed sensors. This wouldn't hurt the brakes, as long as you don't do this all day long. In normal operation, hauling the bike down from 70 to 0 in a panic stop will put more strain on the brakes than this method for sure. 

I'm going to try this, but I need to buy a vacuum set for 4 carbs since I don't know anyone that has one.

Any feedback on my theory would be appreciated.


I witnessed this procedure. 4th gear was used, modest brake pedal used to apply drag/load on the rear wheel. I don't recall speed/RPM used, but I'm thinking somewhere up in the mid-high 3000 range. Reports after the fact from the bike owner were of noticeable reduction of vibration and possibly other seat-of-the-pant performance improvements. Just be careful- doing this isn't any different from riding your brakes down long hills, you can overheat the system just as easily. 

#74 Fred W

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Posted 09 July 2012 - 04:08 AM

I witnessed this procedure. 4th gear was used, modest brake pedal used to apply drag/load on the rear wheel. I don't recall speed/RPM used, but I'm thinking somewhere up in the mid-high 3000 range. Reports after the fact from the bike owner were of noticeable reduction of vibration and possibly other seat-of-the-pant performance improvements. Just be careful- doing this isn't any different from riding your brakes down long hills, you can overheat the system just as easily.


Questions for those who've tried this: 
Did you try adjusting the throttle plates using my "close all 4 air screws at idle" technique first? 
And if so, how much difference (need for further adjustment) was there when you tried the dynamic loaded method using the rear brake? 

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#75 canadianfjrowner

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Posted 09 July 2012 - 05:33 AM

 


I witnessed this procedure. 4th gear was used, modest brake pedal used to apply drag/load on the rear wheel. I don't recall speed/RPM used, but I'm thinking somewhere up in the mid-high 3000 range. Reports after the fact from the bike owner were of noticeable reduction of vibration and possibly other seat-of-the-pant performance improvements. Just be careful- doing this isn't any different from riding your brakes down long hills, you can overheat the system just as easily.


Questions for those who've tried this: 
Did you try adjusting the throttle plates using my "close all 4 air screws at idle" technique first? 
And if so, how much difference (need for further adjustment) was there when you tried the dynamic loaded method using the rear brake?

 


Thanks Fred W
That's exactly what I wanted to try. If after doing this sequence, there is no difference between idle and load, then in the future, the load calibration won't be needed. I'm still waiting for the tool to set it up. I plan to do it at the same time as installing the cruise control, as I will be there anyway. :)

#76 Bungie

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Posted 24 July 2012 - 01:39 PM

Tonight is tune up night (if I can keep the polar bears from bothering me that is). New plugs and air filter going in which means it's time for a TBS.

The plan is to do a regular TBS then check it with the air screws closed as per this technique. If it's out, I'll give it a go, if not, I'll just restore them.

My bike has always felt rough over 4500 rpm. But its got a REAL sweet spot between 3000-3500. Which is just a hair to low for the speed I like to cruise at. I would absolutely love to be able to either make the bike always feel like that sweet spot, or, just shift it up the RPM range a bit. 

I'll keep ya informed. 

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#77 Fred W

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Posted 24 July 2012 - 03:28 PM

Tonight is tune up night (if I can keep the polar bears from bothering me that is). New plugs and air filter going in which means it's time for a TBS.

The plan is to do a regular TBS then check it with the air screws closed as per this technique. If it's out, I'll give it a go, if not, I'll just restore them.

My bike has always felt rough over 4500 rpm. But its got a REAL sweet spot between 3000-3500. Which is just a hair to low for the speed I like to cruise at. I would absolutely love to be able to either make the bike always feel like that sweet spot, or, just shift it up the RPM range a bit. 

I'll keep ya informed.


Very cool, Bungie! That's a data point that has been (to this point) uncollected.

My gut instinct is that you'll find it unbalanced, but I am anxious to her your real observations. Especially if you go through the next step of adjustment and it makes a difference. 

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#78 Bungie

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Posted 24 July 2012 - 06:56 PM

My gut instinct is that you'll find it unbalanced, but I am anxious to her your real observations. Especially if you go through the next step of adjustment and it makes a difference.


Darkness fell before I could try the technique.

Just for reference, my cylinders 2-4 were all relatively close and entirely acceptable, my number 1 cylinder was down quite a bit (this on a Morgan CarbTune). No amount of dicking with the hose on the fitting made any difference at all.

The only way I could get it to rise to even close to the other levels was to completely close the air screw. Obviously, something is haywire. Could be a couple of things I want to check first. I backed it back out 3/4's of a turn to put it back where it was and then buttoned it up for the night (and went for a short ride). Bike feels the same. Go figger :D

Now it could be that the number 1 cylinder throttle plate is out of sync. But I want to eliminate the possibility of any vacuum leaks on that cylinder between the throttle body and the head first, simply because I don't want to be correcting the a vacuum leak with the throttle plate adjustment. I'll get that done tomorrow night and report back. 

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#79 Fred W

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Posted 25 July 2012 - 04:48 AM

Steve,

There is also a possibility that the #1 air screw is the only normal one and the other 3 are all plugged up (or closed down). Make sure that adjusting each screw open and closed has the expected effect (opening drops vacuum in that cylinder). 

Also, it's really easy to get them back to wherever they are now just by counting turns to fully closed and writing them down. 

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#80 canadianfjrowner

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Posted 25 July 2012 - 05:38 AM

 


My gut instinct is that you'll find it unbalanced, but I am anxious to her your real observations. Especially if you go through the next step of adjustment and it makes a difference.


Darkness fell before I could try the technique.

Just for reference, my cylinders 2-4 were all relatively close and entirely acceptable, my number 1 cylinder was down quite a bit (this on a Morgan CarbTune). No amount of dicking with the hose on the fitting made any difference at all.

The only way I could get it to rise to even close to the other levels was to completely close the air screw. Obviously, something is haywire. Could be a couple of things I want to check first. I backed it back out 3/4's of a turn to put it back where it was and then buttoned it up for the night (and went for a short ride). Bike feels the same. Go figger :D

Now it could be that the number 1 cylinder throttle plate is out of sync. But I want to eliminate the possibility of any vacuum leaks on that cylinder between the throttle body and the head first, simply because I don't want to be correcting the a vacuum leak with the throttle plate adjustment. I'll get that done tomorrow night and report back.

 


There are a number of things you need to check. If you are concerned about a vacuum leak between the throttle body and the head, you will need to use a smoke machine. You may need to ask a reputable repair garage (automotive) and see if they can help you. I own a repair facility and have all tools available. I've worked on many toys (snowmobilees etc.) and continue to be surprised by how poorly these machines are put together. Nothing sounds better than a high revving engine all ballanced out.

Good luck 

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Posted 25 July 2012 - 07:23 AM

There is also a possibility that the #1 air screw is the only normal one and the other 3 are all plugged up (or closed down). Make sure that adjusting each screw open and closed has the expected effect (opening drops vacuum in that cylinder). 


After I picked up the Morgan I did my first TBS with it. 2 of the 4 screws were closed, 1 was backed out about 2.5 turns. This is from a 5 Star Yammie dealer. I baselined them all at one turn out and reset the sync. None required more than half a turn either way to balance them to number 3. The bike smoothed out considerably after that one.

Given that the last sync was entirely normal, I'm going to switch to a different tube on the Morgan. Just to eliminate the gauge being the cause. If that checks out fine, I'll do a Quick-Start test on that manifold boot (Spritz some Quick Start around the joints to see if the vacuum jumps). The bike had a valve check last year and maybe something got a little cocked up.

I'll keep you guys in the loop. 

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#82 BlackStar

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Posted 25 July 2012 - 07:37 PM

Just curious here. It looks like the FJR has balance tubes running between the TB's like my FZ1 has. Wouldn't it be better to temporarily plug these to eliminate any flow between the TB's? Realizing that if the vacuum is equal, there shouldn't be any flow. Would it allow one to get the sync even closer? Apparently, they can't flow enough to prevent a bad sync. 
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#83 canadianfjrowner

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Posted 02 August 2012 - 04:41 AM

Well, last night I finally had the chance to do the TBS. I was surprised at what I found. First I managed to set up the fuel tank next to the bike so I had lots of room for adjustments. The bike now has about 1300 miles on it. All the idle adjust screws were set the same at 5/8th of a turn. The hot idle was nowhere near perfect. I went ahead and closed them all and reset the idle rpm to 1000rpm. I could see that the base ballance was way off. I went ahead and revved the bike up in neutral to 4000 rpm and found that Cyl.# 1 and 4 had a lot more vacuum than 2 and 3. Now comes the kicker. In one of my last posts on this thread, I was talking about loading up the engine (like I was riding down the road, since nobody cares if the butterflies are ballanced when revving in neutral)and seeing what kind of vacuum I was getting then. I found it easiest to leave the bike in second gear and rev it up to 4000rpm. Then I applied the rear brake and gave more throttle and kept the rpm to 4000. The numbers were way different than when revving in neutral. I reset the throttle bodies the best I could. The rear brake was overheating by the fourth pull, so I need to cool down the rear brakes with a water spray next time I do this. I reset the idle adjust and rpm when all done. I also installed a Audiovox cruise control so once I get the necesary vacuum hose needed to finish the install, I can take it for a ride. 

I would love to see someone do this TBS on a dyno. I hope someone else will try the same procedure in order to confirm or negate my findings. 

#84 Fred W

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Posted 02 August 2012 - 04:54 AM

Well, last night I finally had the chance to do the TBS. I was surprised at what I found. First I managed to set up the fuel tank next to the bike so I had lots of room for adjustments. The bike now has about 1300 miles on it. All the idle adjust screws were set the same at 5/8th of a turn. The hot idle was nowhere near perfect. I went ahead and closed them all and reset the idle rpm to 1000rpm. I could see that the base ballance was way off. I went ahead and revved the bike up in neutral to 4000 rpm and found that Cyl.# 1 and 4 had a lot more vacuum than 2 and 3. Now comes the kicker. In one of my last posts on this thread, I was talking about loading up the engine (like I was riding down the road, since nobody cares if the butterflies are ballanced when revving in neutral)and seeing what kind of vacuum I was getting then. I found it easiest to leave the bike in second gear and rev it up to 4000rpm. Then I applied the rear brake and gave more throttle and kept the rpm to 4000. The numbers were way different than when revving in neutral. I reset the throttle bodies the best I could. The rear brake was overheating by the fourth pull, so I need to cool down the rear brakes with a water spray next time I do this. I reset the idle adjust and rpm when all done. I also installed a Audiovox cruise control so once I get the necesary vacuum hose needed to finish the install, I can take it for a ride. 

I would love to see someone do this TBS on a dyno. I hope someone else will try the same procedure in order to confirm or negate my findings.



Good report.

And I agree... I do not place much credence in the balance you see when just freely revving the engine to 4k rpm. Any time I have done this after balancing using my adjustment at idle method I always see disparity between cylinders.

Question: After making the throttle plate adjustments at 4k rpm loaded using the rear brake, what did the vacuum balance then look like at idle (with the air screws still all closed)?

You mentioned that they were off initially, what about after making the dynamic loaded adjust? 

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#85 canadianfjrowner

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Posted 02 August 2012 - 05:02 AM

 


Well, last night I finally had the chance to do the TBS. I was surprised at what I found. First I managed to set up the fuel tank next to the bike so I had lots of room for adjustments. The bike now has about 1300 miles on it. All the idle adjust screws were set the same at 5/8th of a turn. The hot idle was nowhere near perfect. I went ahead and closed them all and reset the idle rpm to 1000rpm. I could see that the base ballance was way off. I went ahead and revved the bike up in neutral to 4000 rpm and found that Cyl.# 1 and 4 had a lot more vacuum than 2 and 3. Now comes the kicker. In one of my last posts on this thread, I was talking about loading up the engine (like I was riding down the road, since nobody cares if the butterflies are ballanced when revving in neutral)and seeing what kind of vacuum I was getting then. I found it easiest to leave the bike in second gear and rev it up to 4000rpm. Then I applied the rear brake and gave more throttle and kept the rpm to 4000. The numbers were way different than when revving in neutral. I reset the throttle bodies the best I could. The rear brake was overheating by the fourth pull, so I need to cool down the rear brakes with a water spray next time I do this. I reset the idle adjust and rpm when all done. I also installed a Audiovox cruise control so once I get the necesary vacuum hose needed to finish the install, I can take it for a ride. 

I would love to see someone do this TBS on a dyno. I hope someone else will try the same procedure in order to confirm or negate my findings.



Good report.

And I agree... I do not place much credence in the balance you see when just freely revving the engine to 4k rpm. Any time I have done this after balancing using my adjustment at idle method I always see disparity between cylinders.

Question: After making the throttle plate adjustments at 4k rpm loaded using the rear brake, what did the vacuum balance then look like at idle (with the air screws still all closed)?

You mentioned that they were off initially, what about after making the dynamic loaded adjust?

 


They were way off. BTW, it sounds sooo good when you dial in the idle as you get closer to the ballance point, you can just hear that engine starting to purr. Almost the same when you ballance out a Ferrari v12 with the stupid bosch fuel injection. 

#86 Fred W

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Posted 02 August 2012 - 05:11 AM

They were way off. BTW, it sounds sooo good when you dial in the idle as you get closer to the ballance point, you can just hear that engine starting to purr. Almost the same when you ballance out a Ferrari v12 with the stupid bosch fuel injection.


OK, just to clarify... You are saying that after adjusting it loaded at 4k the vacuum was still way off at idle, right? 
But then you opened up the 4 air screws the same amount and balanced them at idle and that's when you got the great Ferrari sound, right? 

I guess the real proof of the pudding will be in the road test. The times that I have got it it "just right" the difference in vibration is quite remarkable. I'm keeping my fingers crossed that you've found a better method.

BTW - No experience with Ferrari V-12's here, but not for a lack of desire... :P

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#87 canadianfjrowner

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Posted 02 August 2012 - 06:58 PM

 


They were way off. BTW, it sounds sooo good when you dial in the idle as you get closer to the ballance point, you can just hear that engine starting to purr. Almost the same when you ballance out a Ferrari v12 with the stupid bosch fuel injection.


OK, just to clarify... You are saying that after adjusting it loaded at 4k the vacuum was still way off at idle, right? 
But then you opened up the 4 air screws the same amount and balanced them at idle and that's when you got the great Ferrari sound, right? 

I guess the real proof of the pudding will be in the road test. The times that I have got it it "just right" the difference in vibration is quite remarkable. I'm keeping my fingers crossed that you've found a better method.

BTW - No experience with Ferrari V-12's here, but not for a lack of desire... :P

 


Yes, the idle with the air bypass screws closed was off. Quick adjustment was all that was needed. Took it for a spin and wow. No vibration at 65 to 75 mph. Also when you labour the engine at low rpm it seems to pull better without as much complaining. I will do my friend's bike next and see the before and after on that one. 

#88 Fred W

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Posted 03 August 2012 - 03:03 AM

I'd be glad to try this too and add yet another data point. It is all easily reversible if it doesn't pan out. 
Well, that is except for the wear and tear to the rear brake ;)

Now, we may want to dream up a way to make a poor man's dyno type load.

PS - what rpm does 65-75 equate to on a 2nd gen. I know that would be 3800-4200 rpm on my 1st gen. 

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#89 ionbeam

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Posted 03 August 2012 - 03:29 AM

...The rear brake was overheating by the fourth pull, so I need to cool down the rear brakes with a water spray next time I do this...

:ermm: :o Holy warped rotor! Perhaps a fan would be a better idea. 

#90 mcatrophy

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Posted 03 August 2012 - 04:14 AM

...PS - what rpm does 65-75 equate to on a 2nd gen. I know that would be 3800-4200 rpm on my 1st gen.

All is revealed here (clicky).

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Posted Image
 

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#91 canadianfjrowner

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Posted 05 August 2012 - 06:23 AM

I'd be glad to try this too and add yet another data point. It is all easily reversible if it doesn't pan out. 
Well, that is except for the wear and tear to the rear brake ;)

Now, we may want to dream up a way to make a poor man's dyno type load.

PS - what rpm does 65-75 equate to on a 2nd gen. I know that would be 3800-4200 rpm on my 1st gen.


I don't think the speed of the rear tire has as much to do with the set-up as the ability to put a descend load on the engine at 4000rpm and the ability to control it at that rpm as you increase load. I found it easy to raise the rpm to 4000 and then increase load and increase throttle at the same time. BTW. The bike on the centre stand was very stable. I was a bit worried about centrifical forces playing a role in the stability but all was good.
On another note the ability of controlling the rear brake temp. before it gets hot with a water spray shouldn't affect the warpage of the rear rotor. just don't cool it when it is already super hot. Some years ago I had an automotive dyno that I could have used but I sold it 5 years ago. There will be tons of dynos for sale in Ontario by January of next year for basically the price if the steel. There are over 2000 dynos that will be de-commisioned for emisions testing. 

#92 Yamifz1

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Posted 06 August 2012 - 12:12 PM

I recently ( a month ago) bought a 2006 FJR and have been very displeased with it ever since because like many others have noted it hurts to ride it. After a few hours my wrist and elbow are aching and I just want to get off the bike. I bought it because I was looking for similar performance as my FZ1 with a little more comfort but turns out my FZ1 is more comfortable to ride. I knew that something had to be done.

Posted Image

So I finally got a little time to do some work on my bike today. I had planned on doing the throttle spring release, sync the TBs and changing the plugs all at once, unfortunately the plugs were ordered but they did not come in yet. So this morning I released the spring one turn ( definitely a big improvement) and did you Un-authorized TBS minus the engine under load portion as I figured just lining up the plates and then syncing everything would be an improvement. Here is how things lined up at idle with nothing done ti the bike so as to get a baseline.

Posted Image

I then followed the procedure as outlined, which by the way was quite simple except for reaching the screws for the plate adjustments. That required a bit of work lining things up and holding the throttle shut at the same time, none the less I got it done. Here is how things looked when I was finished.

Posted Image

I went out for a very short ride afterwards just to ensure that everything was in working order and right away I saw improvements. The throttle was far smoother and it did not jerk forward in the turns as you accelerated. I also had a fairly noticeable vibration that could be felt in my hands and butt from 4000-4500 RPM. Now I can barely even notice it. I am looking forward to going out for a few hours and seeing what a difference these changes have made. My bike may now be rideable and may only require a change in the handlebar position.

Thanks for the write up and pictures, they made this job far easier. 
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#93 Fred W

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Posted 09 August 2012 - 09:06 AM

I'd be glad to try this too and add yet another data point. It is all easily reversible if it doesn't pan out. 
Well, that is except for the wear and tear to the rear brake ;)

Now, we may want to dream up a way to make a poor man's dyno type load.

PS - what rpm does 65-75 equate to on a 2nd gen. I know that would be 3800-4200 rpm on my 1st gen.
 



Well, today was oil change day. So I propped the tank up and checked the TBS (it's on my regular 5k maintenance list anyway) and checked the balance 5k miles after my last TBS. As is usual, it was off a little bit. 

I then closed down all four air bypass screws and boosted the idle up to 1100 rpm. There was some vacuum misbalance there too. Mostly it was in the most difficult adjustment between #2 and #3. I adjusted that out using my normal procedure (at idle). This still requires stopping and starting the engine to get at that middle linkage adjustment screw, then adjust the two outboard cylinders last with the engine running (much easier).

When I was satisfied all was good I straddled the bike standing up on the pegs (no seat and the tank up) put it into 2nd gear and modulating the rear brake, released the clutch and ran the engine speed up to ~4k rpm. I saw no discernable difference in vacuum there on my bike as compared to at idle. Since I saw nothing that could be improved on by adjustment I didn't do any. Also, FWIW, my vacuums were pretty close as I just revved the engine freely (not under any brake load).

I then opened each air screw 1 turn, readjusted the idle back down to 1100 rpm, and then balanced them at idle again using the air bypass screws. Not much adjustment was required. This last part seems a bit redundant since everything was already balanced at idle before opening up the 4 screws. Some day I may try closing them all down and leaving them there to see what happens.

Now remember, I am dealing with a 1st gen bike. 1st Gen idle adjust is a screw that adjusts the mechanical stop for the throttle shaft bell crank. My understanding is that 2nd gens use something else related to an air bypass, so that may be the big difference in our results. 

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#94 canadianfjrowner

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Posted 10 August 2012 - 05:32 AM

 


I'd be glad to try this too and add yet another data point. It is all easily reversible if it doesn't pan out. 
Well, that is except for the wear and tear to the rear brake ;)

Now, we may want to dream up a way to make a poor man's dyno type load.

PS - what rpm does 65-75 equate to on a 2nd gen. I know that would be 3800-4200 rpm on my 1st gen.
 



Well, today was oil change day. So I propped the tank up and checked the TBS (it's on my regular 5k maintenance list anyway) and checked the balance 5k miles after my last TBS. As is usual, it was off a little bit. 


I then closed down all four air bypass screws and boosted the idle up to 1100 rpm. There was some vacuum misbalance there too. Mostly it was in the most difficult adjustment between #2 and #3. I adjusted that out using my normal procedure (at idle). This still requires stopping and starting the engine to get at that middle linkage adjustment screw, then adjust the two outboard cylinders last with the engine running (much easier).

When I was satisfied all was good I straddled the bike standing up on the pegs (no seat and the tank up) put it into 2nd gear and modulating the rear brake, released the clutch and ran the engine speed up to ~4k rpm. I saw no discernable difference in vacuum there on my bike as compared to at idle. Since I saw nothing that could be improved on by adjustment I didn't do any. Also, FWIW, my vacuums were pretty close as I just revved the engine freely (not under any brake load).

I then opened each air screw 1 turn, readjusted the idle back down to 1100 rpm, and then balanced them at idle again using the air bypass screws. Not much adjustment was required. This last part seems a bit redundant since everything was already balanced at idle before opening up the 4 screws. Some day I may try closing them all down and leaving them there to see what happens.

Now remember, I am dealing with a 1st gen bike. 1st Gen idle adjust is a screw that adjusts the mechanical stop for the throttle shaft bell crank. My understanding is that 2nd gens use something else related to an air bypass, so that may be the big difference in our results.

 


Did you load up the engine by roughly the same amount as if you were riding? 

#95 canadianfjrowner

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Posted 10 August 2012 - 05:37 AM

As I replied to the last post, I realized that nobody actually measured the amount of vacuum present at 65 mph cruising. I just installed a cruise control, to it will be easy to take this measurement. Once we have this vacuum reading, (which is a measurement of engine load that the MAP sensor looks at), we can duplicate this same load while standing still on the centre stand loading up the engine with the rear brake. Will let you all know the results soon. 

#96 Fred W

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Posted 10 August 2012 - 05:48 AM

Did you load up the engine by roughly the same amount as if you were riding?


Yep, I sure did. After two short runs or maybe 10-15 seconds each (I repeated my first attempt to be sure) my rear brakes were good and hot. 

As I replied to the last post, I realized that nobody actually measured the amount of vacuum present at 65 mph cruising. I just installed a cruise control, to it will be easy to take this measurement. Once we have this vacuum reading, (which is a measurement of engine load that the MAP sensor looks at), we can duplicate this same load while standing still on the centre stand loading up the engine with the rear brake. Will let you all know the results soon.


The vacuum level at 65 mph cruise will be somewhat lower than it is at idle because the throttle butterflies are open. 

The original premise of balancing the vacuums under load was that the engine would be pumping more air, so more flow through the intakes at that rpm. I guess now I am second guessing whether the air flow is that much different when loaded vs unloaded? Yes, the airflow will be greater, but the throttle plates wi