I have a 1980 Special with BS34 carburetors.
It has Uni air filters with shortly mufflers.
Compression on both cylinders is about the same.
There are no vacuum leaks that I can find.
The carburetors were re-build including new throttle shaft seals.
The valves were adjusted, the cam chain was adjusted and the carburetors were balanced.
It has one size over pilot jets.
The idle mixture screw was at 3 1/2 out.
After installing the one size over pilot jet, it idled at about 2000-2500 RPM with the throttle adjustment screw all the way out (too much fuel) (it also bogged down coming off of a stop). To compensate for this I turned the idle fuel mixture screw in 1/2 turn. Still idled to fast so I went to 3/4 turn in. It idles good now and runs strong from a stop and through the gears. It runs great.
Question. I'm getting this backfiring in the left/#1 cylinder exhaust. It backfires at idle and when I let off on the gas to stop or shift. It does not backfire at constant road speed of 25 to 65 MPH.
It's annoying. What am I missing? Any suggestions?
Note: It doesn't seem to backfire as bad as it did before the new pilot jet.
It has Uni air filters with shortly mufflers.
Compression on both cylinders is about the same.
There are no vacuum leaks that I can find.
The carburetors were re-build including new throttle shaft seals.
The valves were adjusted, the cam chain was adjusted and the carburetors were balanced.
It has one size over pilot jets.
The idle mixture screw was at 3 1/2 out.
After installing the one size over pilot jet, it idled at about 2000-2500 RPM with the throttle adjustment screw all the way out (too much fuel) (it also bogged down coming off of a stop). To compensate for this I turned the idle fuel mixture screw in 1/2 turn. Still idled to fast so I went to 3/4 turn in. It idles good now and runs strong from a stop and through the gears. It runs great.
Question. I'm getting this backfiring in the left/#1 cylinder exhaust. It backfires at idle and when I let off on the gas to stop or shift. It does not backfire at constant road speed of 25 to 65 MPH.
It's annoying. What am I missing? Any suggestions?
Note: It doesn't seem to backfire as bad as it did before the new pilot jet.