Just got my first Jet Boat! It's a BAJA Sport 200, with a 454, 12 jf pump. It runs ok, however, it has no holeshot at all. It seems as if the pump does not make enough thrust, even though the engine revs up as high as I dare let it. Once on plane, and running 20 mph or so, the boat runs well, and can shoot a pretty big rooster tail, but seems like there should be alot more. I do not know what cut impeller is in the pump other than that it is aluminum. The previous owner totally neglected the boat, and ran it mainly in very shallow water, so I'm sure the pump has sucked up plenty of sand and rocks. From the little bit I know, it sounds like I need to re-shim the impeller. Can I put a feeler gauge in through the cleanout hole to check the gap, before taking the whole pump apart? Also, I have heard that the front seal on the pump can leak, alowing water into the boat, or cavitation in the pump-causing poor holeshot. I do get some water into the boat while running, but the motor is covered on this boat and you can't see that part of the engine bay while operating at speed. However, The interior and all engine covers a off the boat now to be re-upoltered this week, so I will get to run the boat with the engine exposed, and hopefully find the source of the water comming in. Any help on the holeshot issue would be great! Thanks, Rick

I do not think a feeler gauge is going to be a diagnosis for you. Sounds like the bowl needs to come off and inspect the impeller for damage as well as the bowl bushing, shaft, thrust bearing, etc. These pumps are not hard to rebuild. Get yourself a sealoc manual and start from there. Sounds like you have a lot of cavitation there. Is there a loader, do you have foreign material stuck in the impeller, have you taken the hand hole cover off to see if there is junk in there. Have you crawled under the boat to see what is going on in the intake side.
T.J.

X2, when they get to this point, I think it's just better to tear it down, lay it on the floor and build it right, the amount of grief you can save yourself in the long run will pay dividends in the end.

When they are tired, they exhibit the exact symptoms you describe.

Good luck with it.

GT