2.5L Mercruiser

[zwolfe15]

Hey guys kinda new to the forum but i have a 1987 2.5L Mercruiser With and Alpha One Outdrive that is overheating. When I take it out on the water and at a idle the boat runs anywhere from 130 to 150 degrees once i open it up the temperature just starts climbing all the way up to 220 degrees and when i slow back down to an idle it cools back down to 130 or so in just a few minutes. I replaced the water impeller and took the thermostat out of the motor just in case it was sticking and am getting plenty of water coming from the lower unit.

Anyone got any suggestions?

 

[alldodge]

Re: 2.5L Mercruiser

It sounds like your not getting enough water to the engine when running higher RPMs. When you replaced the impeller did the impeller housing look OK? Are you in fresh or salt water? Are the holes in the outdrive which bring in the water appear clear and open? How long has this been going on and did it start slow or all at once?