I bought a project 94 xp with blown motor.  got a rebuilt block and carb rebuild kit for the boat.  When i have it on the trailer and the hose hoked up the thing runs fine.  i then hauled it 8 hours for a family vacation to put it in the water and it wont start.  pulled it out on the trailer and it starts fine.  With it running i backed the trailer in the water and it dies.  Any ideas?

Maybe check your idle speed, since when it's in the water there is a load on the motor, may want to die.  Try turning the idle speed up

I had the same ski with the same problem.  get a new rotary valve and cover.  if the valve and cover are scorn then you will have a very difficult time starting it on water.  It will fire right up on the trailer.  You may also want to check the rotary valve timing as well.   you will need a degree wheel to do that though. You can get a plastic one from ebay or at a seadoo dealer for short $$. Good to have with older seadoos

Hello,
Carb's ?
Did you rebuild your Carb's ?
If Not ?
Why would you run a rebuilt motor on a sacked out carb. Set - Up ?
I hope you did not Damage that motor !
Carb. main dia.'s wear out !
Rebuild the Carb's or Carb. !
If you can't handle it , Pay the Man ! !

Vert-Moto, on 03 November 2012 - 09:27 AM, said:

He said he bought a carb rebuild kit.

It's the carb! Promise you! I've cleaned about 10 thousand of them I think. Out of the water , no resistance in the pump, in the water it will struggle to keep enough fuel flowing through and feed it......OR you put something together wrong when you rebuilt it. Good luck

Well,
What do the Spark Plug's look like ??
A NEW set will tell you what's going on , Lean or Rich condition ?
If you rebuilt the Carb. Correctly, Setting up the Carb's internal setting's, Correctly ?
Did you miss replacing ALL the intake gaskets ?
If you rebuilt the motor, or had it rebuilt ?
Has a Leak Test been performed ?
Air leaks can result in the same symptom's ???
2-Stroke Basic's !