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Hi everyone. I'm new to the forum having just purchased a 1980 Boston Whaler Outrage 20 a few months ago. The engine on her is a 1998 Yamaha 150 Saltwater Series II carburated two stroke engine that was professionally rebuilt by a local Yamaha dealer in 2008, and has recieved very little use since.
I just got out of the boat after a nice fall ride up the CT river. I ran the boat about 3200-3800 RPM upriver, and on my way back ran a little faster. The problem I had occured above 4500RPM. Previously, I had no problems up to extended (2-4 min) full throttle at 5500RPM.
After I passed about 4500-4600 rpm the engine began to skip and hesitate off and on, and run very rough. As soon as I pulled the power back below 4500, it smoothed out and ran fine. Pushing it up again, and the same problem re-occured, almost as it the ignition were breaking up. I was tinking ignition since if fuel were a problem, or contamination, I would think RPM would make no difference.
So far the thoughts running through my mind are ignition coil failing at higher rpm for some reason, perhaps a fuel pump problem not supplying enough fuel to run that RPM range, fuel filter, secondary engine fuel filter?...but I wanted to check the forum to see if this has been a problem for anyone else, and what it might be. The engine runs great below 4500 RPM and is smooth below that speed..
Thank to anyone who may shed some light for me on this...
I should add, there is plenty of cooling water coming out the telltale, no overheat warning on the gauge, full oil....
Todd
I just got out of the boat after a nice fall ride up the CT river. I ran the boat about 3200-3800 RPM upriver, and on my way back ran a little faster. The problem I had occured above 4500RPM. Previously, I had no problems up to extended (2-4 min) full throttle at 5500RPM.
After I passed about 4500-4600 rpm the engine began to skip and hesitate off and on, and run very rough. As soon as I pulled the power back below 4500, it smoothed out and ran fine. Pushing it up again, and the same problem re-occured, almost as it the ignition were breaking up. I was tinking ignition since if fuel were a problem, or contamination, I would think RPM would make no difference.
So far the thoughts running through my mind are ignition coil failing at higher rpm for some reason, perhaps a fuel pump problem not supplying enough fuel to run that RPM range, fuel filter, secondary engine fuel filter?...but I wanted to check the forum to see if this has been a problem for anyone else, and what it might be. The engine runs great below 4500 RPM and is smooth below that speed..
Thank to anyone who may shed some light for me on this...
I should add, there is plenty of cooling water coming out the telltale, no overheat warning on the gauge, full oil....
Todd
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