1989 Sea Doo SP Running Issues

[dschutt]

Im new to the forum and im glad i found it because there looks to be a lot of good info on here. Im a tech in a yamaha, suzuki, ski doo, and arctic cat dealer. Im a motocross guy, just bought my first sled and now i stumbled across a old sea doo and picked it up real cheap (figured id see if i like the pwc thing before i buy a better one). Its a 1989 SD 600SP. Its in great shape but theres a big problem im having. It starts fine and runs good a majority of the time, but when u give it the throttle it starves for fuel and revs up even when u let go. I know its starving for fuel because it has the optional prime kit (replacemeent for choke) and when its reved up and you prime it a time or two, it falls right back down to idle. Heres what ive done so far. Everything i did hjas been done on land with the flush kit. i dont weant to taker it on the water if its going to gernade.

*Replaced all fuel lines (including ones in the tank, they were falling apart and i read online this was a big problem on these)
*Cleaned internal fuel filters, and the external one
*checked one way check valve off tank, as well as trying to run it with the gas cap off, made no difference
*cleaned fuel pump, checked for pin holes in the diaphram
*Cleaned carbs (PITA to get it them off) checked diaphrams as well, along with passage ways and cleaned pilot circut
*tried re routing fuel lines to see if the pump wasnt strong enough to push the fuel through the curve on the bottom
*sprayed starting fluid around all joints and gaskets to check for leaks.

Thius thing has got me stumped. Anything i should double check or anything i missed?

IM TRYING TO GET THE MACHINE READY FOR THIS WEEKEND ANY IDEAS???????????

 

[- BiRkS_]

It is common for you to rev up the engine on land and have the engine stay at that rpm, or "run away". Only way to kill it/tame this situation is to pull the choke, or primer in this situation. Only way to really tune the engine is in the water. Run a compression test. Cold, fuel selector OFF, and full throttle. Perfect compression is 150. it will run decent at 130-135, but below 125, you'll be shooting yourself in the foot.

Another thing to check are the crank seals (only one you can remotely test is the PTO seal) spray ether there (not carb cleaner, it will cause seals to swell) or my personal favorite, propane. (small bottle, cheap blowtorch end, cut the tip off and run a piece of line from that to near the crank seal. If the rpm changes, then you'll be fighting a lean condition for the rest of the life of the engine

Best thing to do, after these tests is put it in the water and test it out. For the carbs, low speed screws should be turned out 1-1.5 turns out. High speed 0 turns out. For the low speed, if you find you take the ski out for a little then throttle down, and the idle seems to be 2-300 rpm higher, turn the low speed screw out 1/4 turn and that should fix it. The 587 engine is a fantastic bulletproof engine. If you're used to working on sleds. This is the marine version of the 583 sled engine. (notice the block off plate in the top of the head where the thermostat housing would go?)

 

[dschutt]

i did check the crank seals and had no appearent leaks. i decided for the hell of it to pull the return line from the carb to the tank while i had it running and sure enough fuel just trickles out. should it be shooting out? or is this normal? thanks for the response, definitely runs better off idle. wound up around 1 3/4 turns on both screws

 

[- BiRkS_]

Check the pulse line going from the carbs to the engine crank case. Make sure there are no pinholes or collapsed lines. Replace that if in doubt then try again. As for the return, It should have a fairly steady flow, not gushing, but steady. Rev it up to 3000 rpm and see if the flow increases, then higher rpm, it should be less and less.