Gp 1800 in mud. Overheat and cavitate

[Pinhacker71]

Out on river with my son yesterday. I was ahead of him and got into shallows. Sucked up mud, looked like chocolate shake coming out of back. I cut engine and pushed off into deeper water. Started fine and couldn’t go above idle without heave cavitation. Then in about 5 minutes overheat alarm came on. Killed engine. Son towed me back to dock at 3 mph because he got a stick in his impeller and had severe cavitation. Crappy day on river but not many decent days left here so went out anyways. Got home and pulled pump on sons waverunner and pulled stick. Should be fine. I haven’t looked at the GP1800 yet other than looking at pump from back. Impeller and wear ring looked fine. Gonna pull them tonight and also flush really well. Anything I should look for.

[K447]

How fine are/was the mud particles?

Thinking about the narrow water passages in the intercooler, the exhaust water injection, and the plastic water inlet/screen in the jet pump.

There may also be some smallish water flow holes in the exhaust manifold gasket?

Really fine silt should eventually flush out, but bigger dirt particles might get lodged in a few places?

You can use the factory water flush fitting with strong water pressure to flush the engine and intercooler.

Start engine, then turn water on.
Flush while monitoring the water side and rear exits, then turn water off.
Blip throttle a couple of times to clear the waterbox, then turn engine off.

Engine running while flushing of course, but limit the engine run duration to a minute or so at a time to avoid friction stressing the water seals in the jet pump and driveline, which will be spinning without being immersed in water.

[Pinhacker71]

It was very silty. When I got off ski to push it I sunk a foot into the silty muddy mess. No rocks or heavy mud.

[Pinhacker71]

Is it supposed to smoke at exhaust when running on hose? My VX deluxe doesn’t at all

[Pinhacker71]

What should I look for now? Any suggestions?

[Pinhacker71]

[Pinhacker71]

I don’t really notice a smell.

[Pinhacker71]

Ok. That’s a relief. Prop actually looks really good. No overheat warning when on hose.