[jparks]

Posted this in the Polaris forum, but no takers so far. Any ideas?

"So this morning, I fire up my ski in the driveway. Works fine. Get to the ramp, put in, tie up, move my trailer, come back, fire it up in the water--starts and idles until I hit the gas and then it stops completely. Try again--same thing.

Load up, head to the shop.

Three new plugs, Mechanic fires it up--no problem.

Back to lake--repeat first paragraph. Back to Mechanic.

Mechanic fires it up. Works great.

Back to lake. Repeat first paragraph. So it runs out of the water just fine, but once it's in the water, it cuts off as soon as you open the throttle.

Back to shop. Fires up, but it's a little slow to turn over. He's taking it out for a lake test because he can't believe it doesn't run in the water.

Am I a total idiot? Any ideas on the problem?

 

[xxxjimbo]

hey when you run on land does it run with water on or off?

 

[jparks]

Hey Jimbo,

I've only had the ski for a little while and just got the shop manual in the mail, so pardon my ignorance.

You mean am I running cooling water through it when I crank it on land? I'm not doing anything differently on land or water as far as turning anything on or off. Make sense?

JP

 

[Ernest T]

Have you or the mechanic checked the compression? There is no load on the engine when you are running it on the hose, so even a crappy engine will run under these conditions. Put it in the water and you are loading the entire system..........typical symptoms of a kaput cylinder, worn out engine, etc.. Other possibility is problem with the pump, but I'd check compression first. ead_Horse:

 

[jparks]

Compression was fine (all three at 125); he did the pre-buy check on the machine (battery, compression, etc.). Took it out for a lake test and said that it was running a little lean and needed some warm-up time before opening the throttle. He's going to fine-tune the carbs and hopefully we'll be good to go.

Took him a 6-pack of beer just because he's been so cool to spend this much time on the machine (off the clock).

 

[xxxjimbo]

yeh the reason i was asking did you have the water on or off was because mine had a blown head gasket and when you would crank it with the water off it would crank but if water was on before you started it it would water foul plugs and would not crank thats all i meant.

 

[JHappe]

Possible solution

I have a 93' SL750. Exact same situation. I talked to a couple of marine mechanics.. here's what they told me to check.. I did and it runs.

They told me that I had a fuel restriction in the carbs/fuel line.

The other day I finally had a chance to look at it and found that two of the diaphrams were partially stuck to the cover and all 3 fuel filters inside the carbs had small pieces of junk in them. I put it all together, dropped it in my neighbors lake and no problems.

I hope this works for you. By the way it does have the Mikuni 3 outlet fuel pump.

Good luck!!