KZ1300 Carb Rebuild - from z1300.com

Apologies if some of the pictures appear out of sequence. This entire article has been produced for those unfamiliar with these carbs although others may benefit as well. Everything described and pictured is done so with ordinary tools and supplies. (some slightly and easily modified). I have personally learned volumes from this rebuild and would appreciate any technical corrections being brought to my attention.

Finally got the last of the polishing done. Not "Show-Room" by any means but a huge improvement over the original condition. All the adjustments that can be pre-set have been done and now simply need to put them on my bike and sync them, set up the fast-idle/choke adjustment and tweek the idle-air screws by EGT to get each cyl. dialed in. Of course that is assuming that everything is "A" OK and the bike will actually do an intiial fire-up on them as pre-set and that they will subsequently accept the final adjustments and run as required (planned).

Since starting this project and documenting it on this forum I have discovered (as I'm certain many already are aware of) there is a wealth of info already out there that encompasses this topic in various formats and some in great general detail although specific subject matter and finer points on these Mikuni carbs. is little to none. Hopefully what i have put forth is both helpful, accurate and informative to a point of actually being useful. Even if it's only informative for one person !

Cheers and Merry Christmas.

ATTENTION BILL: Sorry dude by I hijacked your "Gift" idea ! see the last photo.
 

After some substantial time taken to accomplish the work which has been documented on this forum I am VERY HAPPY to announce the'79 carbs were installed on my '80 today and after a few minutes of tweaking, they are running the engine as hoped ( expected) but not without some frustration and anxiety !

Needless to say they are equipped with "the Brass floats". I adjusted the 'throttle sync" statically (by "eye-ball"" along with an arbitrary 3.5 turns on all the idle-air screws. Installed them on the bike and turned on the auxiliary fuel supply and the center carb. started puking fuel like there was no tomorrow !! WTF ! Took them off, removed the #2 bowl and checked the float for free travel. ( Hey - anythings possible , right?)The float appeared OK and with the aux. fuel supply connected to the carbs still on the bench the needle-valve appeared to be OK too ! WTF ! Put things back together and returned them to the bike and voila !.....Another good douching of fuel !!! WTF ! Back to the bench and this time removed the needle-valve. Found a piece of aluminum (see photo) stuck in the valve-body. I can tell you it didn't come from the fuel source as I have 2 filters to deal with this nonsense so I can only conclude that it was from my fuel-line mod. which required the drilling and tapping of the end on the right-hand carb to accept the 1/4" MPT. Trust me when I tell you I cleaned-out this area with enough compressed-air to supply a small planet ! So it goes to prove the point that no matter how meticulous you are - shit can still happen !
And to put another smile on all your faces I'll share this as well: While re-assembling the "demon" needle-valve I dropped the tiny retainer spring ! An hour later I found it - by accident. Dropped it again ! #*"F@!~ ! Not so lucky this time. Fortunately I had a spare valve so I robbed the retainer from it. GUESS WHAT ?
F&%#K)(*&^% ! Another half-hour on my knees with a flash-light but no luck. One last chance: I robbed the only one I had left which was from the bench-carb. I use for making the floats. Needless to say I changed my install technique and got this one on successfully! I'm pretty confident that some time next Spring when I am cleaning out the shop, I'll find both of them, after I've stepped on them and rendered them useless!

Note to self: Make a jig to manufacture needle-valve retainer springs.

Once the nonsense was dealt with the carbs sync'd easily and the carbs are good to go....so to speak.

In conjunction with a syringe, this is what I used to flush-out the '79 carbs in the recent rebuild article. I did not have it when I cleaned the original '80 carbs on my bike several years ago. This may explain why the '80 carbs were on and off and stripped and re-cleaned 4 times before the bike would idle correctly.
With the other standard methods of cleaning accomplished I used this apparatus to flush backwards and forwards several times using lacquer-thinner. Connecting and blocking the various ports alternately, ensured every gallery and port was cleaned and flushed. Aside from a tiny piece of scarf from the threading required for the fuel line mod. which came off when the fitting was installed, the cleaning with this method proved thorough the first time. The carbs were ( essentially) installed once, dialed in and remain on the bike.
Everything used is everyday simple bits and pieces. A modeler currently on a bit of a break, I had the hand pump and silicone fuel-line. The silicone tubing does not like lacquer-thinner so a vinyl tubing would be preferable.
This is something easily made and adaptation from your own ideas can refine it from this point. Now my "secret" is out !