300/440/550 Js 550 problems

[1WHITE2500]

I have a 92 js 550 last season the motor and carb was rebuilt. It ran great all season, then this summer it starts and runs great outta the water but when i put in in the water it will start but it bogs down and almost dies.
these are new to me so i dont know where to start.

 

[jetski9010]

Did you check for exhaust leaks yet?