650/X-2 Help my pump is cavitating bad.

[TheCoz43]

I just put back together my motor, and it ran good for the first hour and no cavitation, The next time out it started cavitating on me. It does it almost all of the time at both high and low rpms, I did get it to go again for a little bit, I tried to silicon the pump better, no luck. My motor is pritty built, 650 with keihnin 44 carb, head exhaust pipe, box flyweel ect. I just cut 3" off the back and moved steering back 5" and added a trim lever, now I can't ride, I have a stock skat track prop, could that be my problem, The clearance is tight. Could it be something in my fuel system? I was reading another thread, and they said it could have some thing to do with my fuel. Could it be my mixture? Or the H and L screws not adjusted right? The motor sounds good and revs good, but just doesnt go anywhere?

 

[WFO Speedracer]

Carb adjustments have nothing to do with pump cavitation, how well is the bearing housing sealed to the hull? Also just because it won't go does not mean its cavitation, I had a lake call last year where they said the boat was cavitating, turned out to be a bad needle and seat in the carb.

 

[TheCoz43]

I put new bearings and seals in the midshaft and siliconed the holder well. Could it possibly be my crank seals? The motor seam so rev good has decent response just wont hook up.

 

[TheCoz43]

Found a weak spot in my silicon on pump shoe. I was in a hurry trying to get on the water, took pump apart, put on freestyle pump cone and will reasemble carefully. I still want to be able to take it apart again to change the prop so I guess I will use silicon for now. Hopefully will be all good tommarow, going to ride pismo, anyone going out?

 

[waterbox]

did that fix it?