2024-10-28 DJs Tenere Valve Fiasco

2024-10-28 DJs Tenere Valve Fiasco

It started out easy enough. Will you help me do a valve check on my Tenere?

The valve train is identical to your FJR 1300. It should be easy he said.

Do you have a factory service manual I asked?

No, I have all the information I need off of the web. The manual is expensive.

So the disassembly begins.

Not too bad yet.

Do you want me to get markers to identify the connectors?

No. Each connector is different and the cabling is only so long.

Don said, removing the valve cover was kind of difficult.

 96,000 miles, this is the first valve check.

We left witness marks everywhere to ensure the timing was correct on reassembly.

x 

x 

Before we got to measuring, we attempted a compression test. For some unknown reason, we could only get about 90 PSI or so. Not sure why.

FJR and super Teray shims or identical. I have plenty.

We will get inconsistent readings on the exhaust cams.  Later, we found out that Teneres have a decompression mechanism which operates off the exhaust cam.

So we soldered on anyway. That was a second mistake.
The first mistake was not to have a factory service manual which contains reliable information.
It also provides information for when there is doubt.

x 

x 

See Don. See Dan wince. He will be crying later when the bike goes to the dealer.

x 

Now for the rest of the story.

Not knowing about the decompression release, and that it had to be disabled to get a good measurement on the exhaust valves, I threw the towel in. Took the bike to Herb. He adjusted the valves and installed the valve cover too.  Herb explained that on the end of the cam there is a centrifugal mechanism which activates the decompression. It has to be disabled to ensure accurate and consistent exhaust valve measurements.

He also explained that to install the valve cover you first must glue the gasket to the cover, let it sit for a day so that is really good and stuck. Then, on the right hand side of the bike, loosen up the electrical panel to pull it away from the valve cover area. Doing so allows just enough clearance to install the cover. But it is still a bitch.

Get the bike back, put everything else back together. Reconnect all the connectors, route, the hoses, wiring, blah, blah, blah, blah, blah blah blah.

Go to fire up the bike and nothing. It will crank, but no signs of combustion.

We checked all six coil overs, and determined that one spark plug was not firing. We substituted the spark plug to determine the spark plug was good. We moved to coil over to prove all coils were good. I broke out the digital scope and determined that there was no signal going to the coil over, meaning a wiring problem. Or possibly an ECU. Or possibly a crankshaft position sensor?

I also probed the fuel injector connectors. No signal there either. What the fuck over?

Took the bike to Yamaha Santa Maria when we found out it had two factory service recalls. One of which was for something in the wiring harness. Not sure what it was.

At first, they said, the bike was out of time. It would be eight hours labor. Yikes. They said because it was out of time it would not fire. Dan called bullshit on them and said that when we squirted ether fluid directly into the chambers, the bike fired.

Next day the dealer called and said they found the problem. Dan had evidently reconnected to connectors improperly, he got them crossed. Apparently the two connectors are identical, and within the service loop to allow them to become connected.

Dealer said they swapped them and the bike ran great, come and get it. 

Lessons learned

1. Never start any work on a new platform if you don't have a FSM.
2. If the 'customer' doesn't want to pop for a FSM, stop right there.
3. Two people working on one bike does not work. Who did what becomes very confusing.
4. Even though it rarely happens, connectors can become mixed up.
5. Authorized dealerships will try to get your money. At a shop rate of $150 an hour, and eight hours, the bill would be beyond belief.
6. Installing valve covers on this platform is a real bitch.

The end.