90 model omc 4.3 getting hot and I just cant figure out why!

[whitehairdude]

1990 model 4.3 with omc outdrive. Boat only overheats while idling thru no wake zone or as soon as you drop a skier and are trying to retrieve them I mean hot! 240+ it will cool as soon as you take off again. I have changed the impeller 2 weekends ago and while it was out I flushed water from the engine waterpump back and from the muffs to the raw water impeller. Everything flows fine! I found out it didnt have a t-stat in it so I put a 160 in it and it still does it as of this weekend. I just got thru pulling the water pump off the motor and took it apart, all looks good impeller wise so!!! NEXT??? I dont know what else could cause it to get hot. You can idle it up a tad (barely making a wake) and it will start to cool down but if it just in gear, it will smoke its self in a hurry..Screens appear fine also on lower unit..

 

[Don S]

Re: 90 model omc 4.3 getting hot and I just cant figure out why!

Did you replace the oring seal on the pump housing and use some sealer on the seal? How about the gasket under the plate when you took it apart the first time? Did the SS plate come loose from the drive and tear the gasket.

 

[whitehairdude]

Re: 90 model omc 4.3 getting hot and I just cant figure out why!

The water (engine) water pump has obviously been into before due to the red silicone. I just cleaned it up and resealed it with the black stuff I use on everything else that holds fluids. Im currently in the process of removing the outer drive so I can replace the gimbal bearing and whatever else needs changing while Im in there! Something sure is noisy on it back there!!

 

[Don S]

Re: 90 model omc 4.3 getting hot and I just cant figure out why!

I'm not referring to the engine pump, on a marine engine, that is known as a circulation pump. I was referring to the water pump on the back of the outdrive. Known as a raw or sea water pump.

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[whitehairdude]

Re: 90 model omc 4.3 getting hot and I just cant figure out why!

Gotcha, Yes, I did seal them back up with the aformentioned black silicon. I got the lower unit pulled and think I may have found my culprit! (Only thing Ive really found wrong with it so far) . The brass tube that the water comes from the lower unit into the upper part had a rubber seat that was installed wrong. The tube had the rubber seal all smashed up and blocking the passage somewhat so I took it apart and glued it back in right and stuck the tube in it till it dried. Gotta get a new gimble bearing before I can put er back together and try it all over again!