OMC 4.3 overheating

[toyotakid]

AFter winter storage the my 1989 is running hot. The thermostat is good and I put in a new impeller even though the old one looked pretty good with one little crack. The water flow from the outdrive to the engine seems slow or non-existant. When the muffs are on on the outdrive the water flows to one side of the impeller housing. If I run water directly to the thermostat T the exhaust manifolds are very cool. Any ideas and suggestions are appreciated. Thanks

 

[boat127]

Re: OMC 4.3 overheating

when you said when run to thermostat. are you running the impeller dry? that will ruin the impeller.

but you did replace the impeller did you replace teh gaskets too? you said the thermostat looked good. i would replace it anyway. is the cooling system rusted out in the water passages.

 

[toyotakid]

Re: OMC 4.3 overheating

I replaced the thermostat last year and this year I pulled it out and checked it in hot water. It works fine. I also left the thermostat out of the engine and the water continues to not circulate. Yes, I replaced all of the parts that come with the impeller. THanks for helping.

 

[liquidlew]

Re: OMC 4.3 overheating

Sounds like maybe a blockage between the drive and engine water pump. I checked my flow by removing the hose right after the power steering cooler, it should flow really good. You might try dropping the drive in a big rubbermaid tub and filling it with water, and keep the hose in the tub also with the water running. I tried this two years ago and get much better water flow to the engine, so it's like the boat is in the water. I'm not a big fan of muffs, although I use them when I flush my engine with Salt Terminator. If you look at the actual hole in the muffs where the water comes out, it's not very big, at least in the cheapie I got from Walmart!