96 Polaris SLT 780 stalled, won't turn over

[gbarrett]

I have a pair of these and we were running them today. While at near-full throttle, it stalled. I got it to start, but it wouldn't run full open. I nursed it back to the beach and checked what I could. Apart from a corroded battery cable, everything looked fine, but it wouldn't turn over. We towed it back to the boat ramp and then took it home. I pulled the spark plugs, no evidence of water, but the plug from the front cylinder seemed to be fouled. With the plugs out, it still won't turn over. I've got the battery on a charger, but when I tried to start it a few minutes ago, it still won't turn over. I hear the solenoid hit, and it sounds like the starter is engaging.

I am a bit new at these - plenty of motorcycle experience, both 2 and 4 stroke. Any help would be greatly appreciated.

Oh, one other thing - the display doesn't work. Any suggestions on that?!?!

Thanks,

Greg

 

[Billythepokerkid]

Re: 96 Polaris SLT 780 stalled, won't turn over

I can tell you the displays are not reliable on those things, it's 16 years old. You think the starter engages? Does it make any sounds? If so describe them. Try turning the drive shaft by hand, if it does it will eliminate the possibility of a seized piston.

 

[Ernest T]

Re: 96 Polaris SLT 780 stalled, won't turn over

Be sure that something is not wedged in the pump. Spent 2 hours a couple of weeks ago trying to get a friend's ski to start. Finally took a look in the pump and there was a block of plastic wedged between the impeller and housing.

 

[Billythepokerkid]

Re: 96 Polaris SLT 780 stalled, won't turn over

Trying to turn the engine over will also eliminate the possibility of the pump being locked too, as long as it turns. If it doesn't turn over, do like Ernest said and first check the pump. Be sure to pull the plugs before turning it over by the way.

 

[gbarrett]

Re: 96 Polaris SLT 780 stalled, won't turn over

It's not the pump. It's off the ski now and I can't budge it by hand. Ive taken the exhaust and starter off - on my way to removing the motor. Anything I should know about the process?

 

[gbarrett]

Re: 96 Polaris SLT 780 stalled, won't turn over

Found it! The front rod broke, shrapnel in the crankcase. The other two pistons and cylinders look great. I guess it's time to start looking for parts. I know I need a new crankcase as this one is broken, probably a new crank, rod, one piston & cylinder.

Can anyone recommend a good source for parts?

 

[Billythepokerkid]

Re: 96 Polaris SLT 780 stalled, won't turn over

So with the plugs pulled and the pump off the motor won't budge? If there is no water in the cylinder, my guess are you blew an oil line or the oil pump quit working and the motor seized, you somehow got water in the crankcase and again the motor seized, or you weren't getting water in to cool it off, you had a bad temp sensor, the motor got to hot and seized. Either way the motor is shot and for a 96 Polaris you are better off buying another one, preferably not a Polaris. They are not good skis. But if you are pulling the motor anyway, remove the exhaust manifold, removed the driveshaft, the control box, the plug wires, the intake manifold/carbs, the muffler going into the water box, and all the fuel, oil, and water lines. You should be able to reach the motor mount bolts by this point. There are 4 of them, take them out. The motor only weighs like 100 lbs so you should be able to muscle it out. When its out, pull the flywheel over and put a wrench on the crank and see if you can free it up at all. If not you are gonna have to take the whole thing apart to see if you can find out what happened. Again my recommendation......part it out and get what you can for it, or keep it for parts for your other ski and get something a little more reliable, you will spend more on that ski to fix it than it's worth. No matter what, something caused that thing to seize, if you have to rebuild the top end you are looking at $300+ plus your time and that's probably best case. You can get a mid 90's Seadoo for a few hundred more.

 

[Billythepokerkid]

Re: 96 Polaris SLT 780 stalled, won't turn over

Must have been typing at the same time. You can try sbt, a new motor is like $600 or something like that or Ebay for used parts. But again this repair is going to cost you more than thing is worth. The NADA on that ski is $500 in good, running condition. But do what you want, just food for thought.