96 xp wont run in water

[2 96xp]

I am a new owner of a 96 xp. The top end is brand new, carbs are rebuilt with mikuni rebuild kits, new N&S, correct pop. It runs great on the trailer bogs out in the water. Runs a little by feathering the throttle. Idle is set at 3000 out of water. I did the rotary timing as per spec. The clearance on the rotary valve is good when checked with a feeler guage. The only thing I noticed was that when the lower end was assembled the cases are not seamless, the upper cases sticks out a hair more than the lower case. Could this be causing my issues?

Thanks Todd

[sea-one]

post a picture of that

[2 96xp]

I didn't take a pic when the cover was off. I will hopefully take a pic in the next day or 2. Could that possibly cause my problem, there is no scoring or much wear on the surfaces.

[Myself]

Pistons are in backwards or a gasket did not seal.

[Brokenxp]

I had a similiar problem and seemed fine on the trailer but not so good/sluggish in water. Mine was a pto piston skirt got scarred up. Pulled it apart to inspect and that's what I found. In water I had to constantly feather the throttle to get it going. But that was just mine. I had thought it was a tuning problem til I went through the carbs and it didn't help. Good luck. I'm kinda new to the whole watersports thing.

[2 96xp]

The pistons were in backwards when I got it, I luckily caught it before it junked the motor. The top end was good so I honed it and put the pistons in correctly. I installed a new base gasket using indian head gasket sealer, on the cylinder o rings I used Honda bond in the groove, the big o ring on the head and the water jacket got nothing, the carb gaskets were coated with permatex. I did reuse the o ring for the rotary valve cover. If there is an air leak I should be able to spray the area around the outside of the rotary cover and hear an increase in rpm I think.

thanks for the help