Seized 717 engine or driveshaft?

[Supermechanic97]

So I just got a 1997 Sea-Doo GSI 717. I ran it for like an hour and a half and then it died in the lake and it would not restart. It has some safety lanyard connection issues which would cause the engine to randomly shut off and then I would fiddle with the lanyard to make it restart. But this time it would not restart, it would just click and say 12v low. Tried spinning the fly wheel and it was completely seized. So I got the jet pump off and that spins freely. Can the driveshaft seize? Or is it for sure the engine? Of course they had to seize with the clamp connection facing down so I can’t get the clamp off of the driveshaft. Any suggestions are welcome! Thanks.

 

[racerxxx]

It's done now than likely. After you bought it so you do any maintenance before you too it out? It's ok to start these old skis for a short but but you MUST rebuild the carbs and replace the fuel lines, and fuel selector before hitting the water. 2 stroke skis need a good fuel system to operate properly and for longevity. Unfortunately, from your description so far it doesn't sound promising.

 

[Supermechanic97]

I haven’t replaced any fuel lines yet, but it started right up and idle fine and was smoking good there’s weren’t any signs of it starting to overheat before it just quit from the lanyard shorting out.

 

[JeremyD615]

Unfortunately it sounds like this one is actually seized... I’d say that there’s a good chance that it wasn’t shutting off because of the lanyard, but because it was lean and beginning to seize. Like Racerxxx said, you MUST have a properly working fuel system in order for these things to last... Especially this time of year, there are quite a few people that pop in with exactly your story. “It ran great for 30 minutes, and then died and won’t restart.” It’s almost always from taking the boat out before doing their fuel system maintenance.

 

[racerxxx]

It's not an overheat. It's lack of fuel. They can idle all day long. If those carbs aren't spotless you run the risk. I only ever for a ski up that's new to me to make sure the electronics works. No revving, nothing. Then it's a complete tear down if everything. It's 23 years old, they need stuff, it's unfortunate but until you can turn it over and get a compression test gonna have to assume the worst.

 

[Supermechanic97]

Unfortunately it sounds like this one is actually seized... I’d say that there’s a good chance that it wasn’t shutting off because of the lanyard, but because it was lean and beginning to seize. Like Racerxxx said, you MUST have a properly working fuel system in order for these things to last... Especially this time of year, there are quite a few people that pop in with exactly your story. “It ran great for 30 minutes, and then died and won’t restart.” It’s almost always from taking the boat out before doing their fuel system maintenance.

Well, it did have a lanyard problem caus

Unfortunately it sounds like this one is actually seized... I’d say that there’s a good chance that it wasn’t shutting off because of the lanyard, but because it was lean and beginning to seize. Like Racerxxx said, you MUST have a properly working fuel system in order for these things to last... Especially this time of year, there are quite a few people that pop in with exactly your story. “It ran great for 30 minutes, and then died and won’t restart.” It’s almost always from taking the boat out before doing their fuel system maintenance.

e I would have to fiddle with it to even get the starter to spin at all almost every time I would start it. I agree tho that it’s the fuel system that most likely cause it to seize. Any way to unseize it and hop it will run again with fuel system maintenance?

 

[Supermechanic97]

How would I even know it was running lean?? It revved up to 6,550 rpms and was pulling almost 55 mph no problem for an hr.

 

[SIMPLEARKANSAN]

Remove the starter and see if the engine can be hand turned with the PTO.

 

[JeremyD615]

You can pull the driveshaft and use either an impeller tool or a chain wrench to see if you can break it free, but generally they are done once they lock up like that...

 

[racerxxx]

Put oil in the cylinders, let it sit. Most of us have an impeller tool, you could put that into the PTO ( the white disc that the driver shaft goes into) and use a wrench to try and break it free. Or be barbarian and (cringe) use a pipe wrench in the PTO. Keep in mind there is a grease fitting on it and you don't want to break that.

The best thing about a 2 stroke is they ALWAYS run the best right before the grenade.

Just look back thru the last 4 pages of threads, I'm sure there are several fuel system threads or issue relating to fuel systems. We see this stuff year in year out with guys who pick up a good deal, starts and idles, previous owner says it ran great when parked 2 years ago. New guy goes out has a blast and it shits the bed. It's all about the maintenance. Sorry if it sounds like we're being harsh it's just reality unfortunately. Stick with it, don't give up we're all here to help you gain the knowledge you need to keep the ski in tip top shape.

Only other thing I could suggest, but I hate to do it, is pull the head of the engine. I'm sure one of the pistons isn't going look like the other. But, it's a slippery slope once you start to pull things apart.

 

[Supermechanic97]

Thanks for y’alls help! So some good news maybe... after putting a little wd40 in the cylinders, I used a pipe wrench after taking the grease zurk off and with very minimal force it broke free! What do y’all make of that?

 

[Supermechanic97]

Should I just check compression, and if it’s good, rebuild the fuel system and put new oil lines on and an oil filter and give it another go?

 

[racerxxx]

Yep, can't hurt. Maybe you'll get lucky. Screw the compression tester in, ground the spark plug boots on the orange tabs. Hold the throttle wide open and report back. We'll let you know if your compression is good or not.

 

[Supermechanic97]

Yep, can't hurt. Maybe you'll get lucky. Screw the compression tester in, ground the spark plug boots on the orange tabs. Hold the throttle wide open and report back. We'll let you know if your compression is good or not.

Thanks! Will do either tonight or in the morning.

 

[racerxxx]

Cool keep us posted

 

[racerxxx]

The wd-40 may falsify your reading a little bit, but not too much

 

[AKnarrowback]

The best thing about a 2 stroke is they ALWAYS run the best right before the grenade.

Too true.

The best time to ride, and the biggest time to be concerned, when running sleds (winter) is when your machine is "running stronger than it ever has".

The carbs decide if your motor lives or dies, they need to be perfect or bad things happen. If you run lean you will burn a piston and be doing a rebuild.

There is a straight stretch on the river that runs through a cold air pocket near my house. As winter goes on there is always an ice streak where everyone one gets top speed, the problem is the section is typically 10 to 15 degrees colder than the surrounding area. You may be at -15 at the start of the run and -30 at the end when you are max temps in the combustion chamber, most guys hold it wide for a mile and chop the throttle hard for the corner. Chopping the throttle produces a sudden lean condition and has burned many motors coming into that corner.

 

[Supermechanic97]

Too true.

The best time to ride, and the biggest time to be concerned, when running sleds (winter) is when your machine is "running stronger than it ever has".

The carbs decide if your motor lives or dies, they need to be perfect or bad things happen. If you run lean you will burn a piston and be doing a rebuild.

There is a straight stretch on the river that runs through a cold air pocket near my house. As winter goes on there is always an ice streak where everyone one gets top speed, the problem is the section is typically 10 to 15 degrees colder than the surrounding area. You may be at -15 at the start of the run and -30 at the end when you are max temps in the combustion chamber, most guys hold it wide for a mile and chop the throttle hard for the corner. Chopping the throttle produces a sudden lean condition and has burned many motors coming into that corner.

Interesting... so I wonder if the safety lanyard repeatedly shorting out and the last time it shorted out before it minorly seized I was wide open throttle.

 

[Supermechanic97]

I wonder if that could have contributed to the problem.

 

[AKnarrowback]

Interesting... so I wonder if the safety lanyard repeatedly shorting out and the last time it shorted out before it minorly seized I was wide open throttle.

No. Only if you had spark igniting a lean condition that already existed.

Seizures on PWC's is from a constant lean condition not a momentary glitch.

I was just emphasizing how carbs and fuel to air mixtures can kill a motor. PWC's run in a constant air temp that, usually, only gets warmer and will cause a rich condition.

Sleds have a reverse scenario. They can be jetted good for one temperature but encounter significant temp drops that can damage a motor even when the carbs are perfect.

We did a 90 mile run where it was +25F when we left and finished in air temps of -50F. The last five miles were running wide open at speeds near 110 mph, the whole time I was waiting for my motor to seize, I don't know how it didn't. Out of five of us two burned motors on that last stretch (both Polaris).

 

[Supermechanic97]

Do you think it’s better to premix or use the oil injection system? I’m a little scared of oil injection systems.

 

[mikidymac]

Oil injection is perfectly safe on the Seadoo’s.

Also if it seized which it sounds like it did, it doesn’t matter if you broke it free, the damage is done and you need a new top end. Once the aluminum starts to transfer from the pistons to the cylinder it snowballs and there’s no coming back.

 

[JeremyD615]

To add to that, right now you’re looking at a top end. If you get it freed up and run it until it blows, you may be looking at a complete rebuild... Do you risk the bottom end to see if you can make this top end live a little longer?

 

[Supermechanic97]

I have a question about lean mixtures. I was told that my mixture was lean and I need a carb rebuild. But my plugs are nice and black. That doesn’t indicate a lean mixture... am I right??
Btw I’m gonna do the compression test tonight after work and I’ll report back the readings.

 

[Supermechanic97]

To add to that, right now you’re looking at a top end. If you get it freed up and run it until it blows, you may be looking at a complete rebuild... Do you risk the bottom end to see if you can make this top end live a little longer?

By a top end rebuild do you mean, just honing the cylinders and putting on new rings? Or do I need new pistons too? (And of course the gaskets)