Valve Adjustment Nightmare!

[~TABASCO~]

Is that a serious question coming from you?

I'd be impressed if he can pull a head to check the valves with the TB and Exhaust still attached to it.

Unfortunately, if he threw the cam chain, it is very likely at least one piston became very intimate with some valves.

With any luck the damage will be contained to the top end of the motor and the bottom end can be pulled apart for inspection/cleaning only.

ac

Yea for sure, I've been working on motorcycle engines for about 30 years. He's got some bent valves but pulling front and rear he will be able to determined the ones that are. Or just pull the head, he is going to need to pull it anyhow. I would also double check the screen on the oil pump and pull the oil pan. I'm sure he will get'er all done.
Looking forward to reading the rest of this post. I've had other concerns with that cam chain tensioner. Wounder what he/we find out about that.....

 

[sail2xxs]

So how did it go?

In fact, if you don't mind, can you give an accounting of how many valves total have been shimmed in your incredible 100,000 mile journey?

I just want you to know that you are directly responsible for my faith in the longterm future of my bike. Simply amazing.

I picked the bike up after hours and haven't had a chance to talk to the dealer yet. Hoping to get the details tomorrow, and will post. This bike is great - and the support from Yamaha when the bike isn't running right has been excellent.

Chris

 

[Bigbore4]

Or...
Turn the cams so all the lobes are pointing away from the valves on one cylinder. Do a cylinder leakage test. Repeat on the other cylinder. That will show damage you cannot see by looking at the valves.

And ya never know, maybe, just maybe ya got lucky and the leakage check will save you a tear-down.

I aint had to do mine and aint read up yet, but did you retract and or otherwise cycle the cam chain tensioner when you had it apart? When you remove the cams the chain goes slack and the spring extends the tensioner. It was called out in the FJR manual.

Good Luck!

 

[avc8130]

Yea for sure, I've been working on motorcycle engines for about 30 years. He's got some bent valves but pulling front and rear he will be able to determined the ones that are. Or just pull the head, he is going to need to pull it anyhow. I would also double check the screen on the oil pump and pull the oil pan. I'm sure he will get'er all done.
Looking forward to reading the rest of this post. I've had other concerns with that cam chain tensioner. Wounder what he/we find out about that.....

He's got shavings in his oil. That motor needs to come completely apart if he expects a long service life after this instance. All of the oil passages need to be cleaned. The main bearings need to be cleaned and inspected. Journals should be cleaned and inspected. The oil pump needs to be cleaned/inspected. His rotor is probably covered with shavings. Luckily these modern engines have a lot of magnets in them (CPS/Rotor/etc) that tend to pick up shavings rather than let them cycle around the engine forever.

Sure, he could figure out if he has a bent valve without pulling the head, but he's never getting all of that particulate out without a full tear down. It sucks, but it is the truth.

What worries you about the cam chain tensioner? Lots of bikes these days are using hydraulic tensioners. The main reason is people complaining about "ticking" from the old school ratchet tensioners when they were "between" teeth.

I'm not going to lie. I WISH I was close enough to go lend a hand. I LOVE tearing down motorcycle engines.

ac

 

[avc8130]

Or...
Turn the cams so all the lobes are pointing away from the valves on one cylinder. Do a cylinder leakage test. Repeat on the other cylinder. That will show damage you cannot see by looking at the valves.

And ya never know, maybe, just maybe ya got lucky and the leakage check will save you a tear-down.

I aint had to do mine and aint read up yet, but did you retract and or otherwise cycle the cam chain tensioner when you had it apart? When you remove the cams the chain goes slack and the spring extends the tensioner. It was called out in the FJR manual.

Good Luck!

The Tenere uses a hydraulic cam chain tensioner. Oil pressure pushes the tensioner "out". Inspecting the tensioner is covered on page 5-19 of the Euro service manual.

It looks like there is a clip that holds the tensioner in "full slack" position for install. This clip must be disengaged after install by pushing on the guide. This is covered on page 5-22 of the Euro service manual.

There is a note to make sure the chain is taught after this process. Any recollection if this was done during the re-assembly?
ac

 

[BWC]

Well you have certainly found some of the effect. Now to keep looking for the cause. A few items of interest. I don't see the clip on the cam chain tensioner rod. Was the clip installed when the tensioner was removed to allow camshaft removal and was it on when the tensioner was reinstalled? A little more checking the oil sump for the clip( good you found the washer)
And after the tensioner was installed was it reset to allow it to tension the chain? Also might want to have a good look at the timing chain as it may have suffered a pretty good shock load when it came off. And I guess we will soon find out if this is an interference style valve train with possible bent valves and piston damage. Hoping this dosen't require a cylinder head removal, but it dosen't look promising. Been there done that

 

[Dallara]

~


I'll say only this...

If that happened to my engine I would never trust it again unless I pulled the engine, tore it completely down to the last nut and bolt, and checked everything top to bottom, stem to stern. There's already been one major setback with this engine, and shortcuts now would only risk compounding the issue with a possible second catastrophic failure. For me it'd have to be nothing less than a complete rebuild, on the bench, and then reinstalling it.

Of course, there is a slight bright side to doing it that way... It gives you the opportunity to make everything you'd like to literally *perfect*, from either simply "blueprinting" it, to doing all sorts of things like a ported head, lightened and balanced internals, etc., etc., etc.

More than anything I feel for you, Jaeger22. I only wish you the best in this ordeal.

Dallara




~

 

[jaeger22]

Thanks guys, lots of good ideas and advice here.
I realize now that I wasn't completely clear about the missing washer. I found it on the floor where it had rolled under some stuff. Not in the engine. I found nothing extra in the engine. So far.
Yes bent valves are my next worry and it is hard to imagine that they could not be bent but I will check.
Yes I followed the procedure for installing the cam chain tensioner. Pushed back and locked the plunger back inside the body, installed it, then pushed back the cam chain with a long screwdriver until I felt it pop and the chain went tight. All seemed well. I am going to re-read all those instructions to make sure I didn't miss anything. I will also study the parts pf the tensioner to see if I can figure out if it failed.

 

[creggur]

Well, if nothing else this thread has reinforced my notion that I will never attempt this myself. Sorry to see this happen, but this kind of stuff fascinates me so I'll be following along.

Again, sorry for the mess, and here's hoping for minimum damage!

 

[jaeger22]

Quick follow up. As we all expected, the valves are bent. I can see that the two intakes on #1 are not closed. And the cam is out.

 

[coastie]

Sorry you are going through this, but I agree, don't take any chances. Pull that engine and make sure everything is perfect. You have us all on the edge of our seats.

Sent from my SAMSUNG-SGH-I747 using Tapatalk 2

 

[coastie]

Quick follow up. As we all expected, the valves are bent. I can see that the two intakes on #1 are not closed. And the cam is out.

This my be a dumb question, but I'm no mechanic. Could the gears you made the marks on have been misaligned when put back together? Or would you have had a problem right away and not 50 miles down the road?

Sent from my SAMSUNG-SGH-I747 using Tapatalk 2

 

[jaeger22]

This my be a dumb question, but I'm no mechanic. Could the gears you made the marks on have been misaligned when put back together? Or would you have had a problem right away and not 50 miles down the road?

Not a dumb question at all, but no the alignment looked perfect and the motor would not run so well if it was off even a tooth. I just checked and my marks on the cam shaft gears is dead on.

 

[jaeger22]

OK I don't understand all I know about this yet but look at the end of the cam chain tensioner, It is ground to a rounded point. It was nearly square in profile before. It is ground evenly all around and at first I didn't even notice because it is so uniform. The grove at the top that you use to lock it back for installation is gone. I am sure this is where all the metal filings came from.

It clearly was rubbing against the chain directly which should never happen. It should just push on the chain guide. And from the amount of metal missing, I think it ran that way for some time. So my new best theory is that when I was installing tensioner, I somehow got the guide out of alignment and off to the side enough to let the plunger slip by and ride directly on the chain. Weak but that is all I have so far. Thoughts?
You can see from this picture that the two little wire clips are still there:

So time to start reading the manual for "Engine removal". But there are a few more forensic things I want to do. Like pull the oil filter and dissect it to see how much junk is in there.

 

[jaeger22]

Well darn, I think I just shot down my own weak theory. I just looked and there does not seem to be near enough room in the cam chain tunnel for the guide to move to the side enough to get out of alignment with the plunger. Much less let it slip by. :-[

 

[wfopete]

Well if you resided in a northern state, I would say on the bright side you would have a good winter project.

You know what they say: When all you have is lemons it's time to make lemonade.

 

[avc8130]

I think you are dead on with your thoughts about the chain guide. I haven't gotten into the Tenere motor yet, but the others I have worked on had a spot that the guide went in and allowed it to pivot as the tensioner pushed on it. I have a feeling yours was not in this position.

What condition is the guide in?

I can see from the manual that the exhaust side guide slides into a slot on the top of the cylinder, just like every bike I have owned. I'm still digging to see what constrains the tensioner side.

It looks like the intake side has a "timing chain guide retainer" that holds the guide. How does that look?

ac

 

[Karson]

Little late, but as we get higher mileage DIY'ers, would someone try and put something together like this?

http://www.klr650.marknet.us/valves.html

EDIT: I'm sure it's in the service manual and detailed in TEXT, but having good, color pics and a heads up on some "gotchas" along the way would prove invaluable.

 

[avc8130]

Little late, but as we get higher mileage DIY'ers, would someone try and put something together like this?

http://www.klr650.marknet.us/valves.html

We have seen your writeups...how close to 26k are you? LOL

ac

 

[jaeger22]

I think you are dead on with your thoughts about the chain guide. I haven't gotten into the Tenere motor yet, but the others I have worked on had a spot that the guide went in and allowed it to pivot as the tensioner pushed on it. I have a feeling yours was not in this position.

What condition is the guide in?

I can see from the manual that the exhaust side guide slides into a slot on the top of the cylinder, just like every bike I have owned. I'm still digging to see what constrains the tensioner side.

It looks like the intake side has a "timing chain guide retainer" that holds the guide. How does that look?

Yes the guides are a prim area to look at. Good chance I didn't get something aligned or locked in place right. It is hard to see how I could get then out of place but I must have found a way. They both look fine as far as I can see from looking down or looking up from the bottom. I will look tonight to see if I can get them out. And yes they seem conventional. The intake side does have a retainer at the bottom but it looks like it is just a pivot pin with a small plate bolted over the top. If it looks like a PIA to get them out I will wait until I have the motor out.
I REALLY want to figure this out before I build the motor. I think I would have to give up if it happens again.