1993 mecruiser 4.3 overheating

[Searay200OV]

Okay, so end of last season boat overheated at the end of the last trip out bringing it back to the dock. 1993 mecruiser 4.3 with alpha 1 gen 2. In a 1993 sea ray 200OV. I replaced the impeller (old one didn't seem bad but two it every two years anyway) still overheated. Made me think the thermostat was stuck. Took the thermostat out to test without one in it. Still over heats. Getting water to the engine water pump but nothing out the prop/exhaust. Engine water pump doesn't have the "dribble or leak" trying to find one last thing to try before taking it to the shop. TIA

 

[Rick Stephens]

Pull the hose off the thermostat coming from the transom on the port side of the motor. It's the water 'IN' line from the drive. Leave it off and turn hose on to your muffs and fire up the motor. Within a short time you should see good flow. There's actually a chart of how much flow, but for an easy starting place, just look and see what kind of flow you get.

Welcome to the iBoats Forums!

Rick

 

[Bondo]

Okay, so end of last season boat overheated at the end of the last trip out bringing it back to the dock. 1993 mecruiser 4.3 with alpha 1 gen 2. In a 1993 sea ray 200OV. I replaced the impeller (old one didn't seem bad but two it every two years anyway) still overheated. Made me think the thermostat was stuck. Took the thermostat out to test without one in it. Still over heats. Getting water to the engine water pump but nothing out the prop/exhaust. Engine water pump doesn't have the "dribble or leak" trying to find one last thing to try before taking it to the shop. TIA

Ayuh,...... Welcome Aboard,....... How 'bout the pump housing,..??

If there's Any wear, it also needs to be replaced,.....

 

[achris]

Check exhaust elbows. If they're blocked up (rust scale in the water passages), then it doesn't matter how much water is being pushed into the engine, if the hot water can't get out, the engine's going to overheat...

Chris...

 

[Searay200OV]

Sorry been offline for a little while with a new born, haven’t had much time to get back after it. Hopefully in the next two weeks I can find some time to tackle it again. Wanting to figure out what’s going on with that then have it either wet sanded and buffed or have it wrapped not really sure yet.

 

[Scott Danforth]

also, back-flush your power steering cooler.

 

[Lou C]

And make sure the ports in your thermostat housing feeding water to the exhaust system are open and not restricted by rust. They and the exhaust elbow water passages are what allows hot water to leave the engine. These raw water cooling systems depend on a high volume of low pressure water in and out.