boat won't run full throttle..

[cford]

I have a 1998 90hp yamaha outboard 2 stroke. The motor runs fine up to about 75% of throttle.... above that, after running for just a few minutes... the overheat alarm comes on and stalls the engine. Let the engine run at idle for just a minute and it goes off and will run fine again(not at full throttle)
I am in the car business not boat business....Please help.

 

[KC4YIN]

Re: boat won't run full throttle..

Sounds like it's time to change the water pump. When was it last done?

 

[cford]

Re: boat won't run full throttle..

prob 3 years. That's what I thought. I bought a impeller rebuild kit today. The box came with a BUNCH of small misc parts. Is this repair something fairly simple or do I need to contact a professional?

 

[KC4YIN]

Re: boat won't run full throttle..

First off a manual is a must if you DIY.

It depends on your level of expertise. If you don't feel at ease with it I would call a professional. I priced this service for my 04 150 4 stroke and it was about $250.00 which includes pressure testing the lower unit.
I will do mine at the end of boating season this year.

 

[oldfordcrap]

Re: boat won't run full throttle..

hi sounds like your impeller needs a change might have a vien damaged its cheap see if it solves the problem or thermostat?