Need advice,Impeller selection

[mrtool2u]

We picked up a 1996 Sea Doo Challenger with a 780 motor,,I believe 14 foot,,what should this boat run for top end. It is pushing to hit 37 at 6500 rpm's. The hole shot in this boat is hideous.
It has a Solas Impeller,17/26 pitch,which is not what the website calls for. Would a 16.5 /23.5 be a better choice and I assume it would help low end. Would the 26 pitch also affect the low end in some way. The best I can measure is around .020 on clearesane between the wear ring and impeller,is this acceptable.

 

[Rob454]

Re: Need advice,Impeller selection

the single motor speedster top speed is about that. the impeller shoudl give you more bottom but you loose top speed with that pitch. The clearance sounds ok. I woudl put a new wear ring. The impeller could be bent. Do you have cavitation or anythign like that when start ing out. Remember top speed #s were given with a empty tank and a light driver so if yo have the whole family on there and doing 37 youre doing well. My v8 bayliner is only doing 42-44 MPh and thats a 19 footer
Rob

 

[JUSTINTIME]

Re: Need advice,Impeller selection

go to the lower pitch
hole shot will help
sounds like u are way over pitched

 

[Jeff Walkowiak]

Re: Need advice,Impeller selection

remove the black wear ring and use a nylon replacement they are white ,20 is a lot of clearance and you are loosing a lot of thrust, your top speed is about normal but your hole shot is bad because of the clearance in the pump.