over heat

[pepmyster]

Ran the engine at the dock and got them up to temp. On Nmea dash reading they topped out at 154*. Revved up several times, never overheated.

[bud37]

Sorry to say , but you won't get high engine combustion heat running an engine with no load at the dock, it needs to be run under load for some time to get a proper heat soak and test. Don't be misled by the engine temp gauge, it is in fact that temp but you are not removing the same amount of heat at no load to maintain that temp.....under load the heat exchangers earn their living....hopefully it is the strainer lids, one thing I learned as I mentioned earlier, those lids are a bit fussy when the gaskets get old and may need some special attention as to how they are fastened evenly then rechecked after running.

One question....has your boat been this way with both engines since you have owned it ?????

[Viper]

Ya as Bud mentioned, running at the dock even above idle isn't going to give you a true picture, you need to take her out on a sea trial, that's why I asked.

I hope I'm wrong but I'm not confident that the gasket on the strainer is the issue. I've seen way worse than that with no ill effects on runability but did result in water leaks at the strainer.

You said they ran fine before you replaced the impellers but everything looked fine at the pump, question; was this the first time you replaced the impellers in this application? What part number did you get? And did you by chance keep the old impellers?

Looking forward to your findings on these and the questions I asked earlier. Weekend homework

[Phrancus]

Ok so let me be the one to put in a positive note then: That lid is a stupid design when it comes to compressing a gasket evenly all around. And the gasket is old, worn and is up for replacement. It also looks like a very simpel gasket, nothing out of the ordinary so getting something new won't be that much of a problem.

Even when this does not solve the problem as a whole, it will be part of the solution.

In the end nothing beats a good sea trial. Even without any problems

[Midnightsun]

That lid is a stupid design when it comes to compressing a gasket evenly all around.

Agreed, even Groco realized it was not the best as the design has been changed at least since 2007 when Midnight Sun was produced as mine is similar to the one below. The top is spin-on by hand and a simple O-ring crushed flat when tightened does the trick and is easily replaced. Here is what they look like now. https://www.groco.net/products/raw-wate ... arg-series

[Phrancus]

Transparent is good, especially that the lid and the container allows visible inspection, screw on lid is better than the one mentioned earlier. And they considered opening it without tools which is smart.

I'd design a drop in (tube in tube) on a gasket and then a manual clamp to press it in place. And a gasket that allows for serious McGyver solutions when things go broke out at sea.

[pepmyster]

The engines did over heat at the dock at the beginning of all this mess. When that happened, The heat exchanger was dry. So that meant it lost it's prime. When I ran it on the water hose through the service port, it was fine. That when even again this morning, got both running at the dock and both sat at 154*. I can't wait, like you guys, to do a good sea trial. Believe me, you guys will know. The only 1 gasket our marina had a was a cork one out of a service kit of 3 gaskets. I would love to be able to find the rubber version again. Perko model 493-7.
Hans,,,,Here is what they look like now. https://www.groco.net/products/raw-wate ... arg-series. I like the drain plug on the bottom.

[pepmyster]

So. Replaced the rubber gasket kit for the top cover of the strainer. Original Perko kits. After that , did 2 1 hour runs on the river, never overheated, ran like a champ. Case closed.