Question on new (88 hrs) 2021 Moomba Craz overheated due to water valve being closed

Need advice please -

Got my boat delivered by the dealer yesterday. Last summer was my first summer so 88 hrs total. Ran perfect last year.

This year after driving it for 5-10 minutes I smelled something found the engine to be smoking. I immediately turned the engine off to inspect a bit more. I called the dealer.

When I turned the boat on again, the engine temp was now 210 and I got error messages - which I hadnt gotten yet when I smelled smoke prior.

I was advised to let the engine cool off then turn it on in small spurts to get back to the launch. I did this only a couple of times when a nice person towed me the rest of the way.

The dealer says that with a visual inspection that no real damage was done, except for an impeller that they had to replace. But all the other parts all look fine. I will get documentation that this occurred and that its their fault. They say that these engines are built to withstand far more than what happened yesterday (not that its ideal). They are lake testing before they bring it back too.

Any other inspections or diagnostics I should be doing or asking them to do to ensure I dont have some bigger damage that wont reveal itself until later?

The burning was your raw water impeller running dry.

210f is nothing, and you do have engine coolant circulating in the block, it was your heat exchanger system that was empty.

Unless you went up to 260+ I wouldn’t worry about it.

Check your oil and check for coolant in oil, if clean, you are fine.

Keep in mind this same engine is used in Ford Superduty trucks and operate at 210f all day under load.

Bummer your dealer f’d up, shit happens, it’s one of those things you never do twice.


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Id make sure they replace the full water pump since it completely smoked the impeller as it can sometimes distort them when they get that hot. Other than that as Larry said having a closed cooling system, the motor is pretty well protected.

I agree with the others. 210 is not a big deal - they usually run at 170 or 180. Just keep an eye on it. If it starts running hotter than 180-190, you still have a problem.

I had something similar happen at the beginning of 2020 with a little over 200 hours on the clock. For me it wasn't the raw water valve closed, but a failed O-ring in the strainer that allowed the water pump to pull a bunch of air in and killed the impeller.

There was one lingering effect: when the impeller shredded, pieces of it got scattered all through the raw water cooling system. It took 2 trips back to the dealer and then finally me taking it all apart myself to get it cleaned out. Did you get to see the failed impeller? were there lots of parts missing? if so, your heat exchangers need cleaned out or you're going to run hot again. The passages inside those are like 1/8", so any little bit can clog one of 3 heat exchangers that are in the circuit. I also found a small blockage in the plastic elbows where the raw water is plumbed into the exhaust manifolds.

The second lingering effect was a failed O2 sensor. It's tough to say if this was because of this event (exhaust getting hot) or if it's just a random failure, but I got Lean Condition faults when running hard after this event. I replaced the O2 sensor that corresponded with the code and that went away. Pretty cheap and easy, just a pain to have your "new" toy throwing faults and stuff!

If anyone mentions a "paddlewheel sensor" getting clogged - that is only on earlier Raptor engines. 2018 (i think, maybe 2017) and up do not have this easily clogged sensor to detect raw water flow.