jhjesse

Cavitation:

Wear ring is probably worn. Take a light and shine in the jet pump. The distance between the impeller and the ring should be less than the thickness of quarter. If there is more clearance than that, the wear ring needs replacing.

If the clearance is good,  then probably the carbon seal ring is bad and needs replacing.  

Chances are better than good that it is all of the above.

I would just replace the wear ring, carbon seal, bellows and rebuild the pump . Always reinstall the pump with a new neoprene seal. Never reuse the old one. Should be good to go.

http://fiche.seadoow...STEM---INTERNAL

http://fiche.seadoow...EM---DRIVESHAFT

Fuel pumps are in the carbs..i.e., fuel diaphrams.

I would check the following:

1. Check the fuel selector valve. It is probably worn out and needs replacing. $30.99  PN#275500098

2. Pull the fuel baffle and check/clean the bottom screen.

3. Unscrew the fuel filter/water separator and clean. Make sure when reinstalling to use a tiny amount of grease on the 0 ring to make sure it seals, otherwise it will not seal and no fuel will get to the carbs.

4. Change any fuel lines that old and cracked.

5. Check diagram and makesure pulse lines are connected correctly, otherwise no fuel will get pumped into the carbs.  

http://partsfinder.o...&d=-FUEL-SYSTEM

Check the oil injector cable coming off the PTO (aft) carb and make sure it has not come loose/broken. If it has,this will make your oil pump run wide open causing you engine to smoke. (Sea Doo failsafe.)

If the cable is still connected, get a mirror and look at the oil inlection pump on the front of the engine. You should see two lines. One on the pump body and one on the linkage. Those lines should be aligned together while the throttle is at idle. If not then adjust the linkage until they are aligned.

If all of the above is correct and your engine still smokes, Get a pop off pressure gauge and pressure check the crankcase to see if it bleeds down.

A crankcase not holding pressure is usually one of two things:

1. RV seal leaking. Can be replaced without removing the crankshaft or splitting the case.

2. Center crank seals. - Full teardown and rebuild

Leaking RV seal or center crank seal. Usually not a big deal.

If the compression is good (140-150psi) on both cylinders, I would just run it. When storing the boat for more that 2 weeks at a time, just pinch the oil line with a hose pincher to prevent the oil from leaking into the cylinders.

You just have to remember to remove the hose pincher before cranking the motor.