You might try Yamalube Ringfree. There is a standard dosage and a shock treatment dosage. Works on 2 or 4 cycle engines. I had a chronic problem with 90 HP Honda outboard that was fuel related and instead of removal and ultrasonic cleaning of the carbs, my mechanic told me to try Ringfree. I added a stronger than normal (but not shock treatment) dosage to the gas and took several good runs around the lake. Second day out it was running fine and have not had any more problems. Expensive though. Worth a try!
Orginally bein' from West Virginia, I knows wat dem ol spadefaces say bout minin': "Any day 'bove ground is ah good one!"
