'92 Nissan 90 hp - no top end speed

[gil91by8]

I have a '92 Nissan 90 hp outboard motor on a 15" bass boat. The motor is clean and runs great when running with a waterhose adaptor. While running the motor after launch, I can't get the boat to go much faster than a quick trolling speed. The alarm sounds just shortly after shifting in to forward. At first, it tries to accelerate and then quickly reverts to a trolling speed. I have cleaned out the carburetors and there does not seem to be any change. What could be the problem?

 

[TOHATSU GURU]

Re: '92 Nissan 90 hp - no top end speed

You need to determine why the buzzer is telling you to stop. Could be an overheat, low oil or water pressure.

 

[gil91by8]

Re: '92 Nissan 90 hp - no top end speed

What do I do to determine that? The buzzer will sound even when the motor has just been started and put into gear. It doesn't do this when it is out of the water. The buzzer never sounds while running the motor at length, in gear at high or low throttle, while out of the water. I don't know if that matters or not.

 

[TOHATSU GURU]

Re: '92 Nissan 90 hp - no top end speed

You pull out your trusty service manual and start troubleshooting.