OS FS-91 Surpass smoking at low rpm
OS FS-91 Surpass (I) mounted in a 90 degree (right sideways) angle. Tank center line is slightly over carb center line as desired.
This OS FS-91 Surpass (I) develops a lot of smoke on the lower rpm. High speed needle is lean without major smoking. Looks like a rich idle needle setting. In fact, the low needle is turned in so far already that a little more right turn and the engine quits running. How can I adjust the low- and middle rpms? It is a Surpass I, and ran for years. Could it be the piston ring is worn out?