ATC 110 Rebuild Question - Cam Chain Tensioner

[mgros483]

I've been reading this forum for months but just finally registered, so I'm hoping someone is paying attention to the new member area....

I just rebuilt the top end of my 79 ATC 110 and have a question. First of all, anyone wondering if you can handle rebuilding one of these, just do it. I did mine in one day and I've never rebuilt a 4-stroke before. Just get the clymer manual and you'll be all set.

OK, so for my question. I got it all together and it fired up, it runs but I'm getting some cam chain noise. The manual has a pretty good section on how to adjust the cam chain, but it doesn't give any benchmarks to start from. I followed the manual when disassembling and backed out both adjustment screws until they were almost all the way out of the crankcase. The manual doesn't say what to do when putting it back together.

The maintenance section has a good writeup on how to adjust it when it's in normal operation, but I have a feeling I'm not even close.

Any tips?

[barnett468]

hello


What is it you don't understand about the manuals description, it is simplified as much as possible?

The abbreviated technique would be just to remove the plug on the bottom, loosen nut with engine idling and turn screw in gently untill noise stops. if screw gets hard to turn and the noise still persists then stop because you have a more serious problem.

Are you sure it is not rocker arm adjustment too loose?


here's another manual maybe this will help you

http://www.kb0nly.info/ATC/index.php?dir=ATC110%2F

[trike savior]

the way to adjust it is to remove cap on bottom of motor. there is also a setscrew on side of engine that locks the tensioner tube. loosen that and then you can scew in as far as you can the screw under motor. u can do this engine running and listen but I prefer to pull cam cover and feel tension on chain. do not tighten too much cause it will force cam against race and cause it to fail. unfortunately on most the engines ive done the tensioner adjusts as far as it can and you will still see slack. this means chain is stretched and you need a new one. good luck let us know what you find

[mgros483]

Thank you, Savior. The question I had was what to do with the lock nut on the side if I was messing with the bolt on the bottom of the crank. So I'm guessing, for lack of a better explanation, the one on the bottom of the crankcase is a 'coarse' adjustment and the side locknut and screw are the 'fine' auto-adjust.

Thank you guys, it worked out.