Kawasaki 650 X2 jetski Problems?

[Marvell O]

I have a 89 650 X2 JetSki it ran great till the other day I was ridding and it starting acting like it had a fouled a plug. So I put new ones in and went back out and it would run good till I leaned to turn then I would lose all my power. I stoped riding now when i go to ride it it will take right off then a few seconds later it looses all it power I checked everything I could think of ,like the compression ,then the pump, and I even messed around iwth the carb to see if it would help but it didn't. Now I dont know what to do. It runs great on my stand with and without water but when you open the throttle up it spits and sputters (bah-bah-bah). So I can't think of anything on my own. Can you please help it is fusterating me.

 

[the Jeremy Vyle show]

sounds like fuel problem to me have you checked your filters when you are leaning the fuel in the tank also leans with you as you will knowbut the pump should still suck the petrol out this is whats making me think its filters and they are poss blocked though you say it runs great on the stand is the carbs diaphram seated properly and the needles are straight i would check these and if still no answers i would check someone who deals with them i dont know where you live but near me is a firm who deal with outboards etc its called
white bear marina ...www.bwml.co.uk/marina/17/white+bear+marina/

they deal mainly with canal barge stuff etc but the mechs may be able to point you in some direction

best of luck