Mercury Sportjet 120 Problems - Anyone Familiar With These?
 

A friend of mine has a little Checkmate Jetboat with the Mercury Sportjet 120. The boat starts and runs fine, but wont get on plane, the engine just starts to rev. Anyone had this problem or have any suggestions. Several people have looked at it with no luck.

is it jet drive? if it is you may need an impellar or some thing may b stuck in the pump housihjng.

Yes. Everything is clear and the impellar is good.

No one has any experience with these?

does it try and move at all or does it just rev? You might double check to make sure there are no obstructuions

Make sure the seal is intact around the intake grate.

I had one of those a few years ago. That's exactly what was wrong. Replace the seal.

for jet skis in general, if the seal around the shaft is bad it allows air in front of the impeller which causes cavitation. May or may not be leaking inside.

Thanks for the replys, I'll check out the seals! I'll post an update when its fixed.

SVL-WARLOCK, yes the boat moves. You could idle to Canada.:drink:

check all seals, air is getting in there somewhere