Uh Oh (maybe) cam chain tensioner

[trbig]

If the bike was running, it hasn't jumped any teeth, the chain is on all the sprockets, and the bike is still in time.

Skids did bring up a good point. You need to make sure the set screw isn't stripped. BUT.. I just don't understand all of this "Pull the valve cover" stuff. As I stated. If it runs, everything is in time. If it runs and is noisy on top, you need to adjust the cam chain tensioner. For some reason or other, the tensioner backed off. No emergency and no drama. Adjust the tensioner again, make sure you get a small torque wrench and that you can tighten the set screw to the proper torque. If you can't, it's stripped. If you can, you just didn't get it quite tight enough the first time. Happens to me all the time after an adjustment. I'm scared to tighten it too much, so invariably, I don't get it quite tight enough and after a hard run, the top end gets noisy because it's pushed the plunger back a bit. Eventually, I get the proper torque and it holds again... until I adjust it again... lol.

So, take 5 minutes and adjust it again. Fire it up and see if it's quiet.


Tod

[Ivan]

when you pull the valve cover
check to make sure the chain is really on the bottom sprocket
I think thats where your problem started
best to do it on the centerstand
on the side stand i bet it slid off the sprocket and jamed between the sprocket and chank
then when it turned over, it jumped time maybe jumped back onto the sprocket

That can't possibly of happened. When these engines jump time, they bend valves. Not just a little bit, but really bend them. If it were out of time, the valves would have bent while it was cranking over and it would not have started, at all, no way no how. Don't believe me? I can post pics of what happens when the chain slips.

Best thing to do is readjust the tensioner and go from there.

Also, the chance of the slack causing it to jump time without the tensioner in the engine is not 100%. I have had my tensioner out numerous times and never had trouble that way. I am sure that TRBig has as well, and it only burnt him the one time, so he was unaware of it the first several (dozen?) times.

Once again, if the engine ran, there is no need to start tearing stuff apart.

[petejw]

When i overtightened my tensioner, (I over tightened the lock nut
resulting in the pressure of the bolt being slack against the tensioner.)
I was able to ride the bike for a cpl of hrs,
I had let it sit for several hours before trying to restart it,
when i went to restart it the bike backfired slightly
before the clunking noise was heard, I bent 4 intake valves.
The bike obviously wouldnt start.
If your bike is still running then your probably lucky enough
that its only the chain that is loose.

[DGXSER]

I just don't understand all of this "Pull the valve cover" stuff.

Tod,

I call it the "Better safe than sorry" methodology.

I have had my valve cover off a few times, and made my own replacement gasket the first time. After that the same gasket has worked fine. So it is basically a no cost option to look in there and make sure so that you definitely do NOT bend any valves. Yeah, I am the worrisome type.

Yeah, I read it the first time, if it runs it is not out of time. All I know is we just finished pulling the head off an XS11 that had a bent valve. The engine did run, not very well mind you, but it ran. The first symptom we saw of the bent valve was trying to synch and it would blow the line off the synch port on that cylinder.

[trbig]

So it is basically a no cost option to look in there and make sure so that you definitely do NOT bend any valves.

Very few people get to take off the valve cover without tearing up the gasket, so most of the time, there is going to be a cost. Plus, if it doesn't leak, it's hard sometimes to get it to that point again.

So... you want to look to see if he bent valves. Why? Are you afraid of bending them again? As stated, if it's running, just noisily, all he needs to do is spend a few minutes and re-adjust if he hasn't stripped the set screw. Just do it like the book and don't remove the adjuster. If he starts it and it pops and backfires, then he got a valve earlier, but if he ran it for 30 seconds, he bent all of them he's going to bend. If he does an adjustment and it's still noisy, THEN I would take the valve cover off to see if a cam cap was loose or something.

But.. again... that's just me, and it isn't my bike.


Tod

[Ivan]

Well, I threw a can of "The right stuff" in my saddle bags for the case that he does need to pull the cover and doesn't have a gasket. Making that gasket from paper would be a PITA.

[DGXSER]

Making that gasket from paper would be a PITA.

Yes, it IS.

[Bigfoot]

I fully agree with Tod. If it started up fine, all he needs to do is properly adjust the tensioner. Unless I missed something, he took the tensioner off without lining up the proper marks and then replaced it. Ran it for a short time and heard the noise. Has not yet properly adjusted it. I really doubt that he even has any problem such as a stripped tensioner bolt. Why pull the valve cover as a start? That should be the next step if adjusting the tensioner properly doesn't work. IMHO

[Ivan]

Well, I went over tonight and took a look at it. BigDick had it torn down already, so we checked the cam timing, and it was ok. Reset the tensioner then spent an hour scraping the old valve cover gasket, and put it back on with some "The Right Stuff". Started and ran fine.

He also demonstrated his siren and new driving lights. Coolness.

Gonna have to get some driving lights.