Question on overheating repair or replace

[Helmsman]

Source of the post Its an open system, so air is not an issue. I do know however, when I first splash my boat I need to goose the throttle a little bit to pull a vacuum and bring the water up to the pump. After the initial start, its never an issue again.
If you are in the water, did you start the engine and check for flow? Fire them up, both should have nearly equal flow out of the exhaust. If not, you have something in the system. I would doubt its scale. You usually only need to use a scale remover if you have good flow and still cant transfer the heat. Scale removers can soften the copper of your heat exchangers, only use them if needed. So, unless you are in an area with zebra mussels, it most likley impller pieces somewhere in the system.

I think you are right. The flow is out of the strainer, to an oil cooler, then a return less fuel can, then the impeller housing, then the transmission cooler, then the heat exchanger, then the exhaust manifolds and out the back. I will pull every raw water hose today and see if I can find the debris. If that doesn’t come up with something, I will pull the heat exchanger and take a look inside each side for issues.

[Helmsman]

Source of the post When you pull the impeller, check the inside pump housing, wear plate, and cam. A new impeller won't make much of a difference if this hardware is worn.

Has she ever been in salt water and if so, for how long?

Viper, the pump housing, wear plate and cam look like they are new. I am not sophisticated enough with this stuff to be sure, but they look good. After I open all the hoses and look for blockages and also look in the heat exchanger ends, I will look at that to ensure it is ok. There is no pitting, or scarring at the wear plate or the pump housing and the cam looks pristine, though, again, I am no expert!

[Helmsman]

Ok. Narrowed the problem to the Heat Exchange. Just ran 1/2 water and 1/2 Ridlyme through using a SeaFlush kit. Will go out at nine and run fresh water through. Will check in the morning with sea flush to see if the flow is fixed.

[Viper]

Fingers crossed

[mjk1040]

Never had a overheating problem per say, but was getting to much steam out the exhaust for my liking. Tried Barnacle Buster and another de-scaler which seemed to reduce the amount of steam I was getting, did a RydLyme treatment and all the steam disappeared. Anyone install the perko flush valves in the raw water line to the sea pumps?

[darrenlife]

I have installed the Groco fitting on my mains, gennie, and AC pump...love them

https://www.defender.com/product.jsp?pa ... id=2755962

Makes winterizing a breeze and also be used as a bulge pump in the case of significant water in the bilge

[bud37]

This is what I am installing...all bronze..

fb31327bc9bb9b6c1666a169eae1217e.jpg

[Helmsman]

Ok. Tested the suction of the engine raw water using the sea Flush system. It pulled really well and the engine heated to 170. When the thermostat opened it dropped to 160. Was worried about blowing a hole in the transmission cooler but the tranny fluid looks good so we might be back to normal. Next step is to buy a new transmission cooler and either boil out the heat exchanger or replace it. With two engines it will make sense to do both, I think. Will run it through the summer and replace at winter layup.

Incidentally, the guys st Ridlyme said the best result would be to circulate the product for 2 to 4 hours rather than pump it in and let it sit. Would make sense to get the inline fixture for winterization and projects like this.

Thanks for the help.! Couldn’t have done it without you guys.