On second trip out this year, we putted around the lake below 2000 RPM, no problem. Then I got it up over 3000 RPM and power fell off and engine died. It restarted, died, restarted, died etc. enough that I got it back to the dock and partially on the trailer before it would not start at all.
I replaced the low and high pressure fuel filters, fuel lines from tank to engine, fuel/water separator filter, checked tank vent, did a gravity flow test on the tank, and did all normal maintenance: plugs, thermostat, changed oil & filter, replaced water pump impeller, changed lower unit oil. Engine runs fine in driveway (at idle).
Only problems I found was OEM air "filter" had decomposed and some of the foam had been ingested by the engine. I replaced it with the new screen version. External hoses from tank thru fuel/water separator had the inner plastic partially decompose - replaced all external hoses. The low and high pressure fuel filters did not appear blocked, didn't have more resistance blowing thru them than the new filters. Plugs looked great, all firing with light grey/brown coloring on electrode (replaced them anyway). The thermostat was frozen in the open state. Looked 90-100% open.
After all the maintenance, engine will start and run fine at idle, sitting in driveway w/ water hose, runs perfect over 15 minutes. Took it out, ran fine first few minutes getting off trailer and near dock, 2000 RPM and below. Made 2 figure 8's at 2000 RPM, no problem. Got it up to 3000 RPM and within 20 seconds power and RPM fell off, it tried to recover, then went to idle. It would die and restart and die/restart enough that I got close to the dock, then it wouldn't run at all. It would try to start, then immediately die.
Engine did not produce any warning beeps when it began to die.
Only fuel available in my area has 10% ethanol.
I replaced the low and high pressure fuel filters, fuel lines from tank to engine, fuel/water separator filter, checked tank vent, did a gravity flow test on the tank, and did all normal maintenance: plugs, thermostat, changed oil & filter, replaced water pump impeller, changed lower unit oil. Engine runs fine in driveway (at idle).
Only problems I found was OEM air "filter" had decomposed and some of the foam had been ingested by the engine. I replaced it with the new screen version. External hoses from tank thru fuel/water separator had the inner plastic partially decompose - replaced all external hoses. The low and high pressure fuel filters did not appear blocked, didn't have more resistance blowing thru them than the new filters. Plugs looked great, all firing with light grey/brown coloring on electrode (replaced them anyway). The thermostat was frozen in the open state. Looked 90-100% open.
After all the maintenance, engine will start and run fine at idle, sitting in driveway w/ water hose, runs perfect over 15 minutes. Took it out, ran fine first few minutes getting off trailer and near dock, 2000 RPM and below. Made 2 figure 8's at 2000 RPM, no problem. Got it up to 3000 RPM and within 20 seconds power and RPM fell off, it tried to recover, then went to idle. It would die and restart and die/restart enough that I got close to the dock, then it wouldn't run at all. It would try to start, then immediately die.
Engine did not produce any warning beeps when it began to die.
Only fuel available in my area has 10% ethanol.