[mafugr]

I have a 2000 Evinrude 90hp 4 stroke or my pontoon. I get out on the water and run around 30min any speed I want and the boat performs flawlessly. Then suddenly I lose power if I am running above 3000 RPM. The boat losses the comes back and losses again. Naturally you drop the throttle back down to a low RPM like 2000. The boat will run just fine from there so long as I do not go over 3000 RPM. Once I try to go faster I run into the same problem...sudden loss of power. If I drop the anchor and sit for about 30mins with the engine off and start back up. I am good again for another 15 to 30 mins running as fast as I want. Then that's about it goes back to losing power and I cannot run over 3000 RPM. The boat has been at the Marina for 3 weeks now. They've replaced the fuel lines checked the separator and that still did not fix the problem. Now I am getting the run around.
Based upon what I have read so far would any agree that they think it is the power pack? Does anyone have any other ideas.

[tashasdaddy]

i do not know 4strokes, but if it were a 2 stroke, i would look at clogged vent on fuel tank, weak fuel pump. coil or power pack heating up and failing.

[mafugr]

Where is the power pack located? Is it easy to find and install?

[mafugr]

OK, we spent some time at the boat shop today. Gas with Ethonol was the cause. We topped the tank off with some gas before we got to the Marina and the gas contained some ethonol. We drained the tank and what a mess. The algea from the tank was all settled in the bottom of the container. Lesson learned.