Cam installation/tensioner problems

[dwhogue]

I recently replaced my cam chain and today I finally had time to put the cams in and some weird things are happening (big surprise with me). After getting the sprockets on and the first two sprocket bolts hand tight, I rotated the motor clockwise to the “C” timing mark to install the tensioner. The tensioner was retracted as it was supposed to be, but putting it in required me to push on it (further retracting the tensioner) while I installed the bolts. Then, when I released the locking bolts, nothing happened because the tensioner was already in contact with the chain guide. Is this normal with a new chain?

Another question… after installing the tensioner, I rotated the engine twice to the “T” timing mark to check the alignment of the dots on the cams with the marks on the middle bearing cap. The first time the dot was off by a millimeter or two on the intake cam, but it was enough to prevent the sprocket bolt from going in. I disassembled everything and did it again, and that time it was the exhaust cam. What causes this? Am I slack one tooth on a sprocket? There is a little slack in the chain when I first put the sprockets on, but after I rotate the engine it tightens up. The engine rotates smoothly with no unusual binding.

Any advice would be appreciated.

[Ken Talbot]

Dave, it sounds like the chain may not be sitting properly on the crankshaft sprocket. When I helped Yukonman replace his chain a while back, we had a bit of a time getting enough slack to get the chain over the camshaft sprockets without it dropping off the crankshaft sprocket and getting hung up next to that sprocket. IIRC, you can see right down into there with a small maglite.

[Jerry]

Avatar

Hey...drop that guy out of the middle and you have a nice avatar....

[TopCatGr58]

**Copy of reply sent to the Yahoo List request!**

Hey there Hogue,
Can't help with the chain, but sounds plausible since it's very tight when new!! Mine was the used one, so it had some slack.

As for the sprockets and lining up the dots, the manual and my experience when putting mine back together "twice" was that the dots don't line up exactly, like you said, a millimeter or so off is okay. You're allowed to then rotate the cam with a wrench a millimeter or so to help align the sprocket mounting hole for the bolt!! Sorry you took it apart, cause you probably had it right to begin with, just needed to wiggle the cam a little to allow a little slack rotation of the sprocket to let the hole line up!!! Sounds like you're almost there!
T.C.

?What guy in the middle, I don't see a guy, just the girls?

[skids]

Dave, make sure that the action of the tensioner unit is smooth and with no burrs that might cause it to hang-up in a slack position. I know you know that, just a reminder in case you are lost in the moment of near-victory.

[MartyA]

When I did mine it lined up fine. Be sure to put the chain on the intake sprocket first. Then when you put it on the exhaust you can push a finger into the tensioner hole against the chain to help get that alignment just right on the exhaust side. I don't think you can be slack one tooth if you do it this way. If the chain is straight across the sprockets, and the bridge fits under, that's it.

And as skids mentioned, that shaft in the tensioner can get roughed up from the bolt being overtightened over the years. Be sure it is smooth enough to slide. After I had the chain in, I bolted the tensioner on and let it snap into the chain, but I never did hear the 'audible click. ' If I recall it was pretty much snug against the chain when I bolted it on, so there was not much movement when I loosened the locking bolts.

[pgg]

Hey dwhogue, it's tricky getting the dots lined up and you need a 22mm spanner to twist the cams to the sprockets. You need patience for sure. Eventually the dots line up perfectly on the 2nd rotation. If they're not EXACT ( 1 or 2mm out is too much) ; You'll need to do it all over again. It's a matter of the correct tooth in the correct chain link.

[pgg]

Basically the main hassle is preventing the chain from slipping along the cranksprocket. Takes not much slack for the chain to skip.

[dwhogue]

Cam installation/tensioner problems

Thanks to all who replied... I ran out of wrenching time shortly after my post (it is my son's baseball season again, and I am coach), but expect to get back to it this week. I have to agree with Ken... this is most likely a problem with me being off a tooth on the crank sprocket side... the tensioner is fine (thanks Sid!), and all of the other posts confirmed what I knew or thought I should try. I am no longer a frequent poster, but you all have once again confirmed that this is the single best source for an XS11 owner in the world. I can not thank you enough. I will keep you posted on my progress.

As for the avatar... JR (used to be on the list some years ago) convinced a couple of pretty young ladies to pose with me for that pic a couple of years ago in Ft. Lauderdale... I am wearing my '98 Sturgis tank top (also the one and only year I made it to XS camp)... I love that pic (my wife does not!)

Thanks again, guys...