95 SEA DOO XP 800

Sea-Doin

Recruit
Joined
Jul 2, 2005
Messages
3
i just bought a 95 xp 787cc.. i bought it from a marina with 0 hrs on rebuild.. rode it 6 hrs thru breakin in 3 weeks time.. kept it full of fuel and oil and rode it easy.. went to fill it back up with the full 2nd tank of gas and it would not start.. pulled starter etc.. wasnt the problem. i pulled head off and a piston had a chunk out of it and the domes were melted. this ski has been rejetted and k & n pipe and hi-po flame arrester on it is all with .10 wiseco pistons.. what could have went wrong here? and should the marina back this motor even tho it was being sold on consignment?? email me at foreman1172@earthlink.net with any info please.
 

Skidooosl

Petty Officer 3rd Class
Joined
Mar 5, 2002
Messages
94
Re: 95 SEA DOO XP 800

if they did the rebuild i think they should back it.
 

Jeff Walkowiak

Lieutenant Commander
Joined
Jun 23, 2004
Messages
1,944
Re: 95 SEA DOO XP 800

I learned to never use wisco pistons in a jet ski, they are forged pistons and great for outboards but the machine shop needs to bore the holes a little oversized due to the forged pistons expanding more than cast pistons, also they have to mike each piston and bore the hole for that piston and mark where it goes as I have not seen a set of forged pistons that are exactly the same size. I did all that and put a set in my 787 engine and they never made it through the break in period, rings siezed within 2 hours, put in some cast pistons and no problems but I did have to re bore the jugs. as for who is responsible for the engine well if they did not guarantee the ski and most places do not, you own it so maybe you can go to the rebuilder and see if they can help you out, but a 787 is best left stock, doing mods just shortens the already short life of the engine, I blow those up all the time, it usually is the rave ralves that cause the destruction, I am currently trying out highley polished raves and trying to see if this helps them to keep carbon off , I suspect the carbon is snagign the rings and hatching the engines. with the pistons melted I would suspect water was leaking in the engine or they were too lean, but the rebuilder can see the parts and tell you what destroyed it. One thing I learned about that engine is the jugs are seperate but the head is one piece, befort placing the head on I use a straight edge and see if the top of the two jugs are exactly even, you would be surprised at how often they are not exactly even across the top, this makes getting a good seal with the head really difficult, and allows the little o ring head gasket to leak water in, right in the spot between the cylinders as that is the place where the least amount of flex occurs. I actually have surfaced the jugs with a body file to get them exactly even across the top. In any event good luck.
 
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