Mercruiser 3.0 running hot

[darterburn]

The temp gauge quit working so I replaced the gauge and the sending unit. The first time I took the boat out the temp went up to around 220. I pulled the thermostat and ran without it and it warmed up to about 120, so I figured the stat was bad. Put in a new 160 degree stat, and it ran up to 220. I don't think the gauge is reading incorrectly because it diesels badly when you shut it off at 220. I've been running it without a thermostat, but that's not a long term solution. Anybody got any ideas? Impeller is fairly new.

 

[Bt Doctur]

Re: Mercruiser 3.0 running hot

replace the impeller or replace the riser. Either water is not getting in the motor or not getting out of the motor.