Pump cavitation issues 98 sportster 1800

[123indyrt]

I bought this boat knowing it had pump issues. Rebuilt the pumps, new impellers.. coming out of the hall they cavitate a little bit still not as bad. I recently had to do an engine transplant. Running more on one engine during break in, at a slower speed the main engine started to cavitate.. what would cause this cavitation. I'm pretty certain that the pump housing is sealed well at the back of the boat..

 

[racerxxx]

Just run both engine equally, you're not doing the new one any favors, or the old one. Just don't beat on it, get on plane, back off and vary the throttles. I never drop below 4k on a jet boat engine break in, once you do I feel as though you're actually putting too much load on it.

 

[123indyrt]

Funny you say that. I am a car engine guy. I've never researched anything about two strokes. All I know is if you cycle it. A little at a time up-and-down higher and higher is how you break it in. I've simply been doing it on a smaller scale lower RPM keep cycling, next run will be a little bit higher and so on and so forth. It's a little bit better I suppose