Thermostat Falure and Overheating Raptor Engine

[PuraVida]

I was out surfing last weekend when my boat overheated. Ran for about 30 min before we lost power and shut the engine off. Blew the lid off the coolant reservoir. My raw water pump is working because I can see water running through my strainer. Had to get a tow in to prevent any damage. Dealer says it is the thermostat. Anyone else with a similar issue on the raptor 400? Roughly 270hrs.

Boat ran fine the weekend before but we never ran it hard because there was still ice on the lake.

[Stazi]

I was out surfing last weekend when my boat overheated. Ran for about 30 min before we lost power and shut the engine off. Blew the lid off the coolant reservoir. My raw water pump is working because I can see water running through my strainer. Had to get a tow in to prevent any damage. Dealer says it is the thermostat. Anyone else with a similar issue on the raptor 400? Roughly 270hrs.

Boat ran fine the weekend before but we never ran it hard because there was still ice on the lake.

Physically look at the raw water impeller and make sure it didn’t lose a cane and block the water line


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[mor3naz0]

Had the same problem and even though water seemed to be going through the strainer, the raw pump had failed.

I had it replaced and all good so far.


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[PuraVida]

Thank you for the responses. I emptied the strainer and it filled almost instantaneously. Will hopefully know more soon.


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[Casey B]

Did you find the issue? Mine overheated and went in limp mode yesterday. The raw water appears to be circulating fine but it continues to get hot. I checked the t star today and it appears to be working properly as well.

[Gene WB]

How did you end up fixing this problem. I am having the same issue.

Gene WB

[Tommy2slow]

Replaced my impeller and still have issues. Still overheating at low rpm. Cools fine above 2K. Replacing the impeller made no improvement. I’m leaning towards a faulty thermostat, anyone replaced this on a Raptor 400, and what is the difficulty rating for this repair?

[Holdmybeer]

It is as simple as you think. Pop the engine plastic cover off and the housing is right there in plain sight. 2 bolts and you are done.

There is a coolant drain somewhere also so you don't make a mess. However, don't you still have warranty...sound like a dealer problem. How backed up are they?

[Tommy2slow]

9 hour drive from the nearest dealership unfortunately. They will probably go good for parts warranty, but it’s going to be up to me to diagnose and repair for the time being.

[Holdmybeer]

If you get the boat to temp and grab the main 2" hose on the top of the engine headed to the heat exchanger canister it should be hard and have fluid in it. If the thermostat isn't working it will be super easy to squeeze and restrict flow further.

Have you had any other issue or work done? Could be an air bubble in the system.