Would you look up my engine and see if there is any updates or any new I need to do... I seem to have some rough idle problems and I need to know how to fix them.. The engine is a Johnson Venom 200 and the manf. date is 10-1997 and serial number is G04420120 . Also the engine puffs white smoke after it has run along time at full throttle , when you slow down and run slow idle just like it would when you start it up in cold morning..