hey guys first time posting over here but i have a 89 js550 any who, last summer i got my ski up and running and i was ridding for a about a hour when my ski just stalled at WOT( almost wot, it sputters if i pull it fully) and it started right back up , i rode back to the truck pulled my plugs to find water shooting out of my head,  i have a aftermarket carb, intake , resonator and k&n air filter and i have to give it a quick shot of ether to start it when its cold, no primer or choke( idk why the last guy did this). I went to start my ski yester day to go ride for the first time this season and i click the starter to hear nothing. i pull my head and my pistons froze i believe, i got them to move one turn but now they wont budge. unless the impeler keeps my motor from rotating then its froze.

now what should i do?!?!

i dont want to spend a lot of money on a sbt motor, i dont really want to rebuild soo this is my plan and i want you guys to throw your brains on it:) .

- pull motor
- bore to the next piston size ( i think i can bore two more times)
-put a aftermarket head on
- paint and throw it back together.

is there any issues ill have? and is there a fuel pump? i also have no rev limiter and idk if i even need one?

 DBOBYZ450, on 26 April 2012 - 06:18 PM, said:

Those things are money pits...sell for parts get  anewer sx   haha

but really I had one and everything is direct conection....check the pump make sure its not jammed or anything...disconnect the motor or pull the motor from the skit then see if it turns over......one of my friends had a bearing sieze up in the pump and locked it up.

If the motor is locked up then you just start from the top work your way down and rebuild it.

If you look on PWCtoday there are tons of old/new parts for those skis floating around I got a new crank pistons cyclinder for 150$.  If you are going to be in there replacing pistons I would do the crank put fresh gaskets seals and then do the pistons,cylinder.  The aftermarket head isnt worth it that much IMHO...a good exhaust is better and more reliable.  The rev limiter was a vacumn limiter on these skis i believe...they are junk and its good its removed.  No fuel pump but the carb works of a vacumn system and pulls fuel in.....if anything is leaking on the carb it probably wont run (do a carb rebuild with a new kit if you are worried)

Use the high temp engine paint and go crazy lol I didi mine green like highlighter....got some funny looks at the harbor when I would pull the shell.  Put a flush kit on it too..you can make your own.

thank you! i think im going to get it running enough to ride and sell and then either a super jet or a ninja 636 bike is in order

Sounds like you may have a leaking head gasket if it filled with water at WOT and not dumping it.

Yes the fuel pump is the round assembly sticking off the side of the carb. It is operated by crank case pulses from a line at the block to the rear part of the round pump assembly.

The limiter(when it was in place) was electronically controlled. It richened the mix if it revved to quick. If it is gone, make sure there is an inline restrictor in the return line, or just cut the wires to the limiter and leave it in place. Those carbs need that restriction in the return line, or else they return so much fuel, they cause an overly lean carb mixture.