My 2000 90 HP 4-Stroke runs rough at 1000 - 2100 rpm (rpm bouncing around 50 units or so), smooth and strong above 2100 rpm. Told by dealer (after $ 350 carb rebuild) that this motor is notorious for varnish build up in idle and/or mid-range jets that leads to lean popping
and you can hear popping (back firing?) in sync with the rpm bounce. His suggestion is to run carb cleaner (powertune) in the gas but not to expect this to necessarily fix the problem for long. Ive noted that a long thread posted by LAspeckking seems to address a similar problem
and he suggests that one shouldnt be shy about taking the carbs apart and cleaning (with the note that adjusting and rebalancing is needed.) Can anyone tell me that my problem is not unusual and that cleaning the carbs is the right solution? Also any suggestions regarding publications available (manuals, etc.) that would assist?
