matbogbry
12-18-2006, 09:17 AM
I just rebuilt the top end on a 1983 ATC110. I had a local shop bore the cylinder and rebuild the head (cut valve seats, ream new valve guides, etc.). I have put maybe 10 minutes on the new engine.
Problems:
1. I can't get it to stay running (it won't idle consistently). The plug is wet and black.
I am fairly confident that the carb is OK because I cleaned it and it has stock jetting (except the main is an 82).
2. The engine runs rough with smokey exhaust - black smoke.
3. The fuel screw does not act right when I try to adjust it (most of the time it speeds up when I go in or out???)
4. I did a compression check and only had about 130-135 PSI (manual says 156 PSI is minimum). I added some oil through the spark plug hole and the compression increased to about 150 PSI.
5. When I turn the engine over slowly, I noticed a "hissing" sound coming from the intake port area. I put my finger over the intake port as I turner the engine over and, as expected, I feel suction when the intake valve is open, BUT, when the intake valve closes, I can feel pressure (air trying to escape) at the intake port.
Please reply and give me your comments on what I need to check and how to solve these issues.
Your help is greatly appreciated.
:confused:
Mat
Problems:
1. I can't get it to stay running (it won't idle consistently). The plug is wet and black.
I am fairly confident that the carb is OK because I cleaned it and it has stock jetting (except the main is an 82).
2. The engine runs rough with smokey exhaust - black smoke.
3. The fuel screw does not act right when I try to adjust it (most of the time it speeds up when I go in or out???)
4. I did a compression check and only had about 130-135 PSI (manual says 156 PSI is minimum). I added some oil through the spark plug hole and the compression increased to about 150 PSI.
5. When I turn the engine over slowly, I noticed a "hissing" sound coming from the intake port area. I put my finger over the intake port as I turner the engine over and, as expected, I feel suction when the intake valve is open, BUT, when the intake valve closes, I can feel pressure (air trying to escape) at the intake port.
Please reply and give me your comments on what I need to check and how to solve these issues.
Your help is greatly appreciated.
:confused:
Mat