2001 GTX 787

[RalphGTX]

Im a new owner of 2 gtx skis, one had no compression on the forward cylinder. I removed the jugs and pistons for replacement and found water below the crank shaft. Being very new to these I didn't think there was supposed to be anything there, is this a stupid question or do I have further issues?

 

[JeremyD615]

There definitely should not be water in the crankcase! The big question is how did it get there?

 

[RalphGTX]

Im certain the guy I bought them from hooked up a hose with out starting it.

 

[Major Woody]

If there is water down there and the ski has been sitting for more than a couple days, your crank and rod bearings are wet. It won't run, so you can't get the area dried out. Pull engine, split case, rebuild. If there are other options, I don't know what they are.
And drive back to the seller's house and kick him in the nuts for being too cool to read the manual.

 

[RalphGTX]

Thats unfortunate news. As I am learning here and reading all the info I can get even I knew not to flood
the engine with a hose connected wrong. Another question if you don't mind, could the oil pump be the cause of the front piston to to break down and the rear looks good? What is the best oil to use on these machines?

 

[etemplet]

How much water was in there and how long was it in there. Engines have been saved that are in this condition.

 

[GGuillot]

How much water was in there and how long was it in there. Engines have been saved that are in this condition.

He's got no compression on the mag cylinder and the crankcase has water in it. There's no way to save this engine in that condition. If he could get it to run that would be a different story, which to do would require a new top end. The best thing to do it pull the whole thing and rebuild/replace.

 

[etemplet]

Dang..... that's the inner seals on the crankshaft. If you are getting that much oil in there then the water might have not had the normal effect. But you have an issue just the same. I have a ski that does that. I installed a valve in the oil line to the rotary valve. I turn it off when I'm done riding.

 

[GGuillot]

Geez...this thread is all screwed up, the original poster never said anything about too much oil getting past the crank seals. But we're at this point after another poster jumps in this thread and asks unrelated questions, so now we have people thinking there's a problem with both water and oil...

Maybe make me an moderator @mikidymac so I can help you sort this kinda stuff out when I see it.

 

[Major Woody]

Is the 787 engine easy to rebuild? How much should I expect to pay if I ask someone to do it for me? Besides some starting issues right now, the cylinders become filled with oil and the engine won't turn over if it sits too long. We have to take out the spark plugs and crank it over until it spits out most of the oil. Thanks!

Please start your own thread and don't confuse people by jumping into someone else's thread asking unrelated questions. Thank you.

 

[mikidymac]

Thats unfortunate news. As I am learning here and reading all the info I can get even I knew not to flood
the engine with a hose connected wrong. Another question if you don't mind, could the oil pump be the cause of the front piston to to break down and the rear looks good? What is the best oil to use on these machines?

Ok, to get back on track it is hard to tell what caused the piston to break.
1. With water in the bottom end you probably have a bad crankshaft and possible balancer shaft at this point so they should be inspected for rust and damage and replaced if any is found.
2. You need to service the entire fuel system and carbs before getting this thing going again.
3. For oil you have to use a full synthetic API-TC rated oil. I prefer the seadoo E-Tec Carb 2-T just because it is easy for me but there is also Mystic and Amsoil Interceptor.

 

[RalphGTX]

Thanks for the info, would Quiksiver synthetic work?

 

[mikidymac]

In my personal opinion no. The quicksilver is no longer API-TC rated and now says it’s for all watercraft but there’s no such thing as a dual rated oil as the specs and additive packages are completely different.
I would suggest researching it and deciding for yourself.