Valve Cover Rubber Needed? (Was Oh Crap!)

Yamaha FJR Motorcycle Forum

Help Support Yamaha FJR Motorcycle Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

dcarver

Well-known member
Joined
Sep 5, 2005
Messages
13,814
Reaction score
3,468
Location
Creston, CA
This piece

3.jpg


That's supposed to fit here

16.jpg


Dislodged when installing valve cover. At first start attempt, it moved and wedged between cam chain and tunnel on intake side just above CCT.

Engine is locked, cam chain incredibly tight.

What to do?

Tried removing CCT but it's under stress duress. Took me 2.5 hours .10 flat at a time. Then it occurred to me that the CCT may not come out if it's fully extended? Is that true or will the CCT clear the frame if fully extended? This is a new style CCT and won't hold the 'compressed' position without the key.

Such a bad day on the lift..

I hated to leave the cam chain and cams and crank under such pressure but decided to quit until daylight. The CCT bolts are at nearly out but thought I'd ask advice here first before making things worse.

If lifting the cams, even with heavy cam chain tension is an option, what's the best loosening technique? Away from cam chain sprockets first then work towards the sprockets or?

This part is wedged on intake side, just above CCT.

Worst case scenario, cut the the cam chain?

Any ideas?

Phook Me.

 
Don,

Are you sure that the piece is stuck behind the intake side of the chain? Because when the engine is running the chain runs down the exhaust side and up on the intake side. There is a chain guide that the tensioner presses against. Maybe that is what you are seeing on the intake side? If so, pulling the CCT should release the chain tension. Or just winding the CCT back with a screwdriver may get you the slack you need.

If the piece is really wedged behind the tensioner guide, you may need to pull out one or both cams.

 
Last edited by a moderator:
What Fred said...

Can't you back off the CCT tension? When working on valves, I back it off with a long-bladed screwdriver and clamp a pair of needle-nose vice grips or a hemostat to the shaft of the screwdriver to hold it. With the cam chain loose, you may have space to work.

Might want to remove the timing cover to get at it from below. The piece might have fallen down.

 
If the part is wedged in the engine then what is the one in the picture??

Don't see how it could travel opposite the rotation.

I think what you are looking at is the tensioner slider.

Pull the timing cover and I think you will probably find the answer.

Read the flow chart.
default_smile.png


 
Don,
Are you sure that the piece is stuck behind the intake side of the chain? Because when the engine is running the chain runs down the exhaust side and up on the intake side. There is a chain guide that the tensioner presses against. Maybe that is what you are seeing on the intake side? If so, pulling the CCT should release the chain tension. Or just winding the CCT back with a screwdriver may get you the slack you need.

If the piece is really wedged behind the tensioner guide, you may need to pull out one or both cams.
Yes. I understand crank rotation and the questioning attitude of it being on the intake side of things. I suspect it dislodged when removing the cover, and fell into the intake crevice. That has some logical merit as the cover is removed via the intake side of things. I wish I had kept my old CCT so I could see what size screwdriver fits the adjuster. I tried to compress the CCT, no real effect. I think the tensioner maybe internally damaged.

What Fred said...
Can't you back off the CCT tension? When working on valves, I back it off with a long-bladed screwdriver and clamp a pair of needle-nose vice grips or a hemostat to the shaft of the screwdriver to hold it. With the cam chain loose, you may have space to work.

Might want to remove the timing cover to get at it from below. The piece might have fallen down.
I'll try again today after a restless night of sleep. Stuff like this gets under my skin and I lock in too heavily. Will search to see if I happen to have a spare CCT and what size screwdriver to use on CCT. It doesn't feel like anything happens when I turn the screw. No feedback, and the two mounting screws are very hard to remove.

If the part is wedged in the engine then what is the one in the picture?? Don't see how it could travel opposite the rotation. I think what you are looking at is the tensioner slider. Pull the timing cover and I think you will probably find the answer. Read the flow chart.
smile.png
The picture was from when I did heavy maintenance on KrZy8 2018 Oct. Here's the part that pisses me right $%#@ off. Back then the same piece came loose and ended up in the cam chain tunnel exhaust side. And I didn't learn.

In this pic, it would have been opposite the red arrow.

1.jpg


I did pull the timing cover and it's nowhere in there. Even tried reverse rotation on timing cover bolt.. only loosened the bolt.

**So here's my questions...

  1. IF the CCT is phooked up, and I can't compress the tensioner, will the CCT clear the frame? Can it be removed if fully extended? Or am I getting into deeper waters.
  2. Is it possible to remove the cams if chain is this tight? I would think not. If not, what's next? Cut the chain?
Sigh.

Gotta run to town, will look at this later.

Thanks for all the help guys and gals.

 
Don;

If I remember correctly the CCT should come out even extended. Mine was when I first removed it. Now I don't know if it was all the way extended. You may have to remove the clutch cover for clearance to get it out. It's been a while since I did this (several times BTW for others) I'm not sure why the CCT won't retract but as you loosen the two CCT bolts and the CCT wants to back out from the spring tension you should be able to retract it. Now the other problem could be that the part is wedged and the CCT is all the way retracted in. Now that's an issue. IIRC Nothing can push the CCT back in, I believe it must be released by screw action so to speak.

Can you make that small "T" shaped key?

I would value others inputs on this I know we have others that have done this.

Good luck.

 
Last edited by a moderator:
I believe that the CCT will come all the way out even if fully extended, but even if it doesn't, by removing the mounting bolts it should loosen enough to take tension off of the cam chain.

 
2019-08-01 Found missing piece from valve cover causing engine lockup at start up.

Took some EndoScope pics in area where I thought MIA valve cover rubber cam chain guide ended up causing engine lockup at start. At first, convinced my ace deduction skills were correct.. These views from intake side top.


Here the cam chain appears to be centered and properly located.


Got the CCT out. YES, it can be removed when fully extended. When removed, the cam chain was still Banjo-String tight indicating the bind was severe and elsewhere.


Once CCT out , could remove intake runner dowel. Don't give me crap. The chain is still banjo-string tight and I don't care if I have to buy a new dowel pin. At this point, KrZy8's life is still at stake..


More EndoScope pics... Where is the MIA part?


Wish I had looked at this more closely.. Would have save 3.5 hours of time...


Because... Here it is. Wrapped around crank shaft cam chain sprocket. At first I thought "The chain was sooo tight it killed the teeth on the phenolic sprocket"... Deja Vu Kz1300 stuff..


But nooo, full steel teeth below..


That poor chain.


Intake side almost relieved.



Removed, cam chain restrained. Foreign material rag in place to keep crap from dropping into oil pan.


The offender.


It's the full piece. No worries of internal motor contamination.

That's it for now.. Lower back is SCREAMING from bending over for hours and troublshooting this bitch I love name KrZy8
 
Great stuff! Figured you might find it with the timing cover off. Guess its better caught by the gear then dropping undetected into the oil pan. Double check timing - could have skipped.

 
I think I would be concerned about how much this "edit" Might Have stretched the Timing Chain as well. JSNS

 
Last edited by a moderator:
I believe you have the caption The offender under the wrong picture. Should it not be under a selfie?

Glad it worked out in the end.

 
I think I would be concerned about how much this "edit" Might Have stretched the Timing Chain as well. JSNS
I agree with bjgjohnsd, New TC would be cheap insurance from future failure. You have it almost all the way apart anyway. The TC Guides should be undamaged since that offending piece didn't get jammed in between the chain and the guide. Might want to closely inspect the CCT to make sure it's functioning properly and not damaged from that tight tension action that occurred.

Hope you don't have anymore surprises. Good Luck!
smile.png


 
Do timing chains really stretch?

Like drive chains of any sort, you will get elongation as the chain wears but this apparent "stretch" is a function of wear in the pins/bushings, not stretching. While this event MIGHT have caused some damage to the chain, it would not stretch it. Hardened steel vs a bit of plastic/rubber - I think the chain wins.

https://www.mromagazine.com/features/the-myth-of-chain-stretch/

Still, replacement might not be a bad idea. There is a small but real possibility that one or more of the pins could have been damaged and if you consider the price of a timing chain vs the cost of a catastrophic chain failure, the case for replacement is compelling.

 
Do timing chains really stretch?Like drive chains of any sort, you will get elongation as the chain wears but this apparent "stretch" is a function of wear in the pins/bushings, not stretching.
Ok not literally stretched, but severely stressed. Sounds like he hit the stater and it locked the motor. Not quit as bad as actually running and locking but stessed none the less. But as said better than piece dropping into the crankcase.
smile.png


 
Holy smokes Don! Great lessons learned and what to watch for. Glad it all worked out in the end. So many puns there...
default_wink.png


 
Part #5

3.jpg


16.jpg


Is this rubber needed? How in the world would cam chain EVER get loose enough between the sprockets to hit cover case? And if so, how much OTHER trouble would the engine be in? Thinking of leaving it out...

What so you?

 
Top