Noise-cam chain?

[Guest]

Started having what I thought might be cam chain noise recently. Read lots of threads on here and checked out things suggested. Adjusted valves while inside checking out cam chain. Had to change two which were a little tight(.02mm), now-07mm. Checked cam chain timing and right at 20 pins as should be, measured cam chain distance between pins and within service limits. Have new rubber on cam chain idler (just replaced this winter). Took off cam chain tensinor and reset properly, appears to be working fine. Checked every bolt inside and made sure tightened to spec. (all were good). Did find very small scrape on inside of valve cover near where chain goes into back of idler. Could have caused the noise. Can't remember if valve cover gasket is oem, but still in great shape and seems thick enough. Cam chain idler is tightened to spec. and touch more, it does seem to move up and down very, very slightly, really have to look to notice. Is that normal? Afraid to tighten further, afraid bolts will snap. Any thoughts or suggestion very welcome! terrylee

[chuck hahn]

Idlers shouldnt move up and down far as I know...thats why the tensioner works out the slack in the chain. Bolts may be tight enough holding the base but the axle the gear spins on itself may be going south. What about the chain guides themselves?? Taken a light and looked down at them yet ???

[terrylee]

Thanks for response Chuck. Front guide is new (this winter), can't seem to see back one no matter where I look, may have to take head off to see? Idler seems to turn straight and not wobble, have a spare from parts bike and seems about the same, teeth seem ok too. Chain seems snug as it should be, don't see any problems when turning motor by hand. Took idler off three times to make sure chain had not jumped any teeth. May try switching idler with spare one to see if makes any difference. I rebuilt tensinor couple years ago and it seems to be working, but knob doesn't turn but a little when engine is running, but does turn consistently. Did file down scrape inside cover a little, put everything back together a while ago and noise is not as loud, but still there. Wondering if I should order oem valve cover gasket to see if that could be part of problem. terrylee

[JTGS850GL]

If I recall, my 82 GS850 idler block had a slight amount of movement as well. The idler has two black spacers and a metal insert that was just ever so slightly longer then the two spacers + idler frame were thick. The bolts passed through the insert that passed through one spacer, through the idler pulley frame and then through the other spacer, When the bolts were tight it still allowed a small amount of movement in the idler. I think it's by design.

[terrylee]

Same thing mine is doing. I think I will order oem gasket and see if that might help, I'm almost certain noise is where chain is slightly rubbing inside of valve cover. The sound is not as loud after I very lightly filed down spot where scrape was inside valve cover. terrylee

[terrylee]

I decided to loosen up the set screw a little more on the cam chain tensioner , was slightly beyond 1/4 turn. Turned it out 1/8 more turn, did seem to help, chain is not so loud, noise still there some, but much better. terrylee

[Steve]

I decided to loosen up the set screw a little more on the cam chain tensioner , was slightly beyond 1/4 turn. Turned it out 1/8 more turn, did seem to help, chain is not so loud, noise still there some, but much better. terrylee

You want it in the range from 1/4 to 1/2 out from "snug".

I have shown many owners whathappens when you turn it farther and it flies apart.
All of them have gone right around 3/4 turn.

.

[terrylee]

Thanks Steve, my concern too. I tried my best to not make it 1/2 turn. terrylee