Help, 1989 Yamaha 200HP Outboard 2-stroke carb engine theRPMs rollback intermittently. The engineidles and runs great for 30+ minutes before having an issue so I need sometroubleshooting/repair advice.
I’ll run 30-45 mins at high cruise RPMs in the 4000-4300range then suddenly the engine will rollback to 3000 RPMs with no throttle ortrim changes. Occasionally it surges and/orslows to 2000 RPM happen as I continue to run home &/or cycle the throttle,that’s the max RPM I can get. The engineappears to enter into a safe mode but I have no alarms for over temp or low oil. If I shut the engine off for a while, she’llstart & cruise again for short distances. Once the problem starts, it's stalled occasionally but usually it keeps running just at thatreduced RPM.
I’ve checked & replaced the fuel filter and the water separatorplus I inspected the vent screen and verified the clean line. I only run ethanol free gas & addstabilizer with each fueling. I replacedthe primer ball and have checked all the fuel lines with no leaks or bad linesobserved. The spark plugs were new thisseason & all look good upon inspection. The console & engine linkages look good on both ends. Thewater pump seems fine and produces a solid stream but I’ve inspected the 2 x temperaturesensors (which are intact and look good) along with the thermostat. I top off the oil system before each trip butconsumption & reservoir appear normal/remain full on each trip.
Again, no alarms or additional engine lights beyond thegreen oil system.
Anyone fixed a problem like this? Thank you
I’ll run 30-45 mins at high cruise RPMs in the 4000-4300range then suddenly the engine will rollback to 3000 RPMs with no throttle ortrim changes. Occasionally it surges and/orslows to 2000 RPM happen as I continue to run home &/or cycle the throttle,that’s the max RPM I can get. The engineappears to enter into a safe mode but I have no alarms for over temp or low oil. If I shut the engine off for a while, she’llstart & cruise again for short distances. Once the problem starts, it's stalled occasionally but usually it keeps running just at thatreduced RPM.
I’ve checked & replaced the fuel filter and the water separatorplus I inspected the vent screen and verified the clean line. I only run ethanol free gas & addstabilizer with each fueling. I replacedthe primer ball and have checked all the fuel lines with no leaks or bad linesobserved. The spark plugs were new thisseason & all look good upon inspection. The console & engine linkages look good on both ends. Thewater pump seems fine and produces a solid stream but I’ve inspected the 2 x temperaturesensors (which are intact and look good) along with the thermostat. I top off the oil system before each trip butconsumption & reservoir appear normal/remain full on each trip.
Again, no alarms or additional engine lights beyond thegreen oil system.
Anyone fixed a problem like this? Thank you