96 Sea Rayder, can't get up to speed!

[acidburn87]

Hey all, I'll make this short and an easy read.

I just bought a 96 Sea Rayder F-16 Jet-Boat w/ the Mercruiser 120 motor. The boat has about 220 hours on it, low for it's age.

If I get 3 people on it, say a total of 550 lbs on the boat, it maxes out at about 33 MPH on open, clear and smooth water (engines at almost 5.5K rpm at that speed too). I just had the intake plate re-sealed at a local marine (they told me it was pulling in air and disrupting the water flow), it helped, but it seems to slow for the HP output of the boat (even with it loosing 30% efficiency, due to it being a Jet Drive).

Any thoughts or ideas? Impeller & Wear ring (which they said "looked alright")??

Any help/thoughts would be greatly appreciated!!

Thanks,
Jesse

 

[kend301]

Re: 96 Sea Rayder, can't get up to speed!

is 33 mph on the speedo or by gps? the speedos are very inaccurate in these boats without proper calibration. Start by checking the ride plate to insure it is flush with the hull and check impeller clearance it should be .010 to .030 for best performance . Finally is the boat planing out at top end or is the bow still up in the air a bunch ?