Asymetric
10-01-2014, 07:53 PM
So I was gifted a 1979 atc 110 that had been sitting in a barn for a good 15 years. I went over everything I could think of. Gas tank cleaned. New fuel lines wi th filter. Carb cleaned (have done tons of car carbs. Pretty sure I got it good). Air filter had turned to paste, replaced that. New brake cable and cleaned/re greased the brake cam thing. Sandblasted & painted the rims before putting on new tires. New front wheel bearings. New plug. Set point gap and timing. Adjusted valves to .003. (They were really tight before)
It runs great. Starts with one medium effort pull. With th e needle adjusted 1 turn out, it revs good ad pulls about as strong as I would expect for such a small 4 stroke.
But the idle is all over the place. It will be high, then low and want to stall out. Sometimes it will idle right where I want it for a minute and then either quit or Rev up.
There is a "clackety" noise in the engine that sure sounds like a loose chain running over a sprocket. I tried adjusting the cam chain tensioner but there was no noticeable change. It doesn't sound extreme, but you can clearly hear it.
Could a loose cam chain cause what I am experiencing? I really don't want it to be that. I am already over budget at about $350 invested and might just drive it as is since you can goose the throttle when it starts to idle down too low. It gives you about 2 second warning when it's going to die.
I would really like everything to be "right" tho since I was thinking about giving it to my nephew for Xmas and finding a bigger one for me.
It runs great. Starts with one medium effort pull. With th e needle adjusted 1 turn out, it revs good ad pulls about as strong as I would expect for such a small 4 stroke.
But the idle is all over the place. It will be high, then low and want to stall out. Sometimes it will idle right where I want it for a minute and then either quit or Rev up.
There is a "clackety" noise in the engine that sure sounds like a loose chain running over a sprocket. I tried adjusting the cam chain tensioner but there was no noticeable change. It doesn't sound extreme, but you can clearly hear it.
Could a loose cam chain cause what I am experiencing? I really don't want it to be that. I am already over budget at about $350 invested and might just drive it as is since you can goose the throttle when it starts to idle down too low. It gives you about 2 second warning when it's going to die.
I would really like everything to be "right" tho since I was thinking about giving it to my nephew for Xmas and finding a bigger one for me.