noisy valve train all of a sudden?

[yotaman423]

hey guys i was ridin my 80 gs850 on it interstateabout 75-80(i was in a hurry) when i got off my exit and stopped at the light the engine sounded like a sewing machine with no oil. im assuming the noise is coming from the valve train or cam chain or something. i did a valve adjustment this winter. so far only rode maybe 1500 miles. cam chain tensioner was rebuilt then also. before i pull the valve cover is there anything i should be looking for? why would it get noist all of a sudden like that. i should add the performance of the bike seen to not have been affected at all. still runs fine picks up good and idles ok its just noisy. any insight would be great thanks guys

[tkent02]

Did you forget to release the set screw on the cam chain tensioner? It should be about 1/4 or 1/2 turn out from tight. If you did forget, it can't automatically adjust the chain tighter as it needs to do. It will get noisier and noisier. Or perhaps like my new 550, the outer spring is wound up backwards?

[yotaman423]

pretty sure i reset the tensioner correctly. like i said it has been quiet until yesterday but you never know. ill re check it when i pull the valve cover

[Lunchbox88]

Did you forget to release the set screw on the cam chain tensioner? It should be about 1/4 or 1/2 turn out from tight. If you did forget, it can't automatically adjust the chain tighter as it needs to do. It will get noisier and noisier. Or perhaps like my new 550, the outer spring is wound up backwards?

The tensioner is supposed to be loose? Wouldnt that allow it to jump around when the chain vibrates?

[yotaman423]

finally pulled my valve cover off to have a look see. what i found is when i rotated the engine by hand at i certian spot the cam chain where it goes under the idler pulley between the cams would be loose and hanging down basically slack in the chain. i tapped on the cam chain tensioner a few times and it seemed to tighten back up so apparently it was sticking all back together and she is quiet and smooth again

[TheCafeKid]

The tensioner is supposed to be loose? Wouldnt that allow it to jump around when the chain vibrates?

With the engine OFF (neve turn the tensioner while the bike is running) you should be able to turn the knob and have it spring back fairly easily. If it takes more than a small amount of effort, the tensioner needs to be pulled and cleaned and probably rebuilt.

Yotaman, I'd suggest pulling your and having a look. It will do it again at some point, and it could be bad bad times if and when it does.

[Steve]

The tensioner is supposed to be loose? Wouldnt that allow it to jump around when the chain vibrates?

The knob on the side is preloaded with a spring (the test that TCK just pointed out). The knob is attached to a screw that goes inside and pushes on the tapered end of the plunger that pushes on the cam chain. The taper is a one-way mechanism that only allows the plunger to move toward the cam chain.

The plunger is also spring loaded to apply the tension to the cam chain. To install the tensioner, you are supposed to loosen the locknut and setscrew, retract the plunger, lock the plunger in place with the setscrew. Install the tensioner, release the setscrew so the plunger estends into position. Lock the setscrew again, then back out 1/4 to 1/2 turn and lock it in that position with the locknut. There is a groove machined into the side of the plunger that allows the plunger to move, but will restrain it from moving too far.

Many people see the instruction to lock the setscrwe after installing the tensioner and don't see (or don't bother with) the "back it out, then lock it" part.

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