cam chain tensioner popping noise

thrasher · Posted: June 16, 2009, 2:28 am Post subject: cam chain tensioner popping noise

so i put a new engine in my bike that was "rebuilt" by my uncle several years ago. i'm pretty sure the engine is about a 1975. for the most part it looked ok and i could see crosshatch in the cylinders so i assumed it was all good. well i went to adjust the cam chain tensioner is that when i turn the engine over with the kicker the tensioner pops. i took the cap nut off the tensioner and immediately noticed that there was no locknut, also the adjuster was ran in a long ways compared to my old bike and the rod was even sticking out a little ways. i backed it off until the rod was flush but instead of just moving in and out a little ways when you turn it over the rod will go in a little then pop and come out about 1/2 inch. plus with it adjusted like this the adjuster wasn't out far enough to have both a locknut and the capnut on there.
what the heck is wrong here? should i just swap the tensioner assembly over from my original engine or is this problem caused by something else

xsjohn

The rod sticking out a little is probably because the copper dampner washer was left out..........and for adjustment is sure sounds like it's cam chain time......guides ..........?

xsjohn

yamaha_dave

Is it necessary to remove the heads to replace the cam chain tensioner and guides or can it be done through the cam chain tensioner mounting plate?

weekendrider

The cam chain tensioner is all that is available through the tensioner hole.
Front guide requires the head be removed.

yamaha_dave

Dang-it!

yamaha_dave

I changed my oil last weekend and found a thin 1" long sliver of hard black plastic. I can only assume it's from the cam chain guide...

weekendrider

I'd bet that assumption is correct.

Retiredgentleman

thrasher;
Try adjusting as follows. Engine hot from riding a fare distance. Adjust the tensioner inward until the in/out motion has stopped. Back off on the tensioner until you have a small amount ( about 1/32" or .031") of in/out moton.

thrasher

well i know how to adjust the tensioner, the problem is that every time you turn the engine over the tensioner makes a loud popping noise and the rod comes out about 1/2 inch. it seems to do this no matter how far in or out you adjust it.

xsjohn

It's hard to imagine a chain being that loose but it does sound like it.......and with the head off you should check the face of the rear tensioner........it could be gone making the chain even appear looser...they do last but if someone over tichtened the chain it can wipe them off.......the snapping noise would be as the cam passes a lobe and tightens the chain....snap...........

have to lift the barrels to change the rear cam chain adjuster.......

xsjohn

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