Sport Jet 90 Wont Move

[JRP1983]

I just bought a 1994 Donzi medalion 152 with the Merc Sport jet 90. The engine starts right up and runs perfectly, but once i put it in the water the boat wont move over 5 mph. I am pretty sure the revers gate is up(unless it falls once i start the boat) There is about a 1/32 to 1/16 inch gap between the impeller and housing. I pulled off the ride plate and the Gasket looks O.K. The engine revs to around 5200 rmp and the impellor is spining because i can see the water shooting out of the back very fast ( could it be air too)...i dont know why the boat will not move...Any help would be appreciated Thanks Justin

 

[Barracuda_Lounge]

Re: Sport Jet 90 Wont Move

I have the same problem when I suck a stick or something in the inlet. However, once it clears the boat runs normal again. Have you tried posting this question on http://pub103.ezboard.com/bsportjetworld. This site is dedicated to our sportjets.

 

[steelcup]

Re: Sport Jet 90 Wont Move

Here is the correct link to that site <br /><br /> http://pub103.ezboard.com/bsportjetworld <br /><br />the peroid on that sentence threw the link off

 

[bret walters]

Re: Sport Jet 90 Wont Move

if the reverse gate is opening when in forward and there is no debris in the pump housing the problem is most likly a warped or cracked ride plate. if this is bent it wil vent exhaust gas into the impeller and cause it to cavitate.