omc overheat

[skcc]

I have a 1983 0mc 230 hp and cannot figure out why it is overheating at about 3000rpm. once she gets hot I slow down to a troll speed she cools down very fast and then i can get on plane again for a minute or two then gets hot again. Changed the impeller whats next?I have just realized there is no thermostat so have ordered one and im changing the water pump would not having the thermostat cause the water to go ight out the manifolds and not through the engine?

 

[JB]

Re: omc overheat

What part of. . . (not engine topics). . .did you miss, skcc?<br /><br />Moving to I/O topics.

 

[Manipulator]

Re: omc overheat

I have this problem too. I had a new impeller installed, I installed a new thermostat, and the manifolds had been changed a few years ago so I know its not them. I checked the risers recently and they are fine too. My temp will hover just under the red mark on the gauge. It does not get in the red but is right on the edge. RPM does not seem to change anything. Whether I'm cranking or cruising it does not matter. Its not always there (near the red) but most of the time it is. I have a 1983 OMC with the 260hp engine. You must have the 305 chevy. Anyway, I think its the gauge. I don't have any symptoms of overheating and have ran it this way for two seasons. Again, get a new gauge and see what happens before you rip the water pump out.

 

[vicsponjr]

Re: omc overheat

I was having a similar problem. Put a new impeller in and it helped a little, but was still getting up to 190-200 after a few minutes.<br />I took the housing off and this time replaced the wear plate (that wasn't worn), cleaned it up and replaced the gasket. Also used some sealer on the housing o-ring and tightened it up real good. Running at about 175 now.