1997 seadoo gtx getting too much oil in one cylinder

[Aaron5555]

I have a 1997 seadoo GTX with a 787 motor getting too much oil in one cylinder. It starts once but sounds rough and smokes a LOT. The second time it turns but does not start. After pulling the plugs, one is soaked in oil. Any help on how to fix this is appreciated.

 

[jjsinaz]

Sounds like a bad internal (RV Cavity) crank seal

 

[Aaron5555]

After a quick search in the forum it looks like the seals are containing an oil bath for the worm gear and they are in the middle of the crank shaft.
Is there a way to split the crankshaft in the middle and change the seals or do I have buy a new one?
I am opening up the engine this weekend.
How should I proceed?

 

[wabash]

If those seals are bad you'll need a rebuilt crank.

 

[Aaron5555]

No one rebuilds crankshafts around Montreal, I have looked around a lot. So I have to rebuild it myself with the help of my friendly neighbourhood machine shop charging $80 per hour and willing to help me out.
So, all I need to know now is what parts to order from WSM and how to split the crankshaft to change the seals?

 

[mikidymac]

Good luck with that. Unless he has done a lot of multi cylinder two strokes and has all the special seadoo clearance spacers it won't work. They take lots of skill and have to be phased and trued perfectly. If you can get WSM parts you can get WSM complete cranks.

These are not DIY cranks and 99% of all machine shops either don't or shouldn't touch them. They are not like replacing crank seals on a car.

 

[DanSquires]

Rebuilding the cranks is pretty specific. I've "dabbled" in a dozen or so 717 and 787 cranksnow, and have spent an absolute ton of hours figuring it out (and am nowhere near what i'd call "proficient" at it) Unless you are planning on rebuilding a bunch of them, just buy a WSM and have a great day.

 

[Aaron5555]

Opened up the engine today. And looks like you guys are right. Buying a new crank is best way to move forward.
Any suggestions on where to buy one or a whole rebuild kit?

 

[Aaron5555]

This is what my 787 looks like when I took it out of a 1997 GTX.

 

[mikidymac]

You should have pulled the PTO before you tore the engine down.

 

[Aaron5555]

Oops. My bad. I forgot to take it off. Can it be salvaged? Or should I order the new crank with one?

 

[mikidymac]

You could try clamping the crank in a big vise or even parking the car on it. A chain wrench usually pops the PTO off. Don't worry about hurting the crank since it will be returned as a core.

 

[Aaron5555]

PTO came off pretty easy after using a vise.
I am buying a whole rebuild kit with a new crank, no core exchange required.
It's a place in Pullman, Washington. "Eastern Washington Sled".

 

[Upallnight]

Oil Valve

PTO came off pretty easy after using a vise.
I am buying a whole rebuild kit with a new crank, no core exchange required.
It's a place in Pullman, Washington. "Eastern Washington Sled".

From the oil tank feed line to the engine you can insert a valve to shut off the oil when you are not using the jet ski. This will prevent oil from accumulating in the cavity. You just need to remember to open the valve before using the jet ski.

 

[mikidymac]

From the oil tank feed line to the engine you can insert a valve to shut off the oil when you are not using the jet ski. This will prevent oil from accumulating in the cavity. You just need to remember to open the valve before using the jet ski.

That will work if it is only filling with oil after sitting a couple days. If it is burning a lot of smoke and leaks quickly your only option is a rebuilt crank.

 

[Aaron5555]

Just talked to the guy at EasternWashingtonSled today, he is sending a new WSM crankshaft with a full rebuild kit. That should solve my problem for sure.

 

[mikidymac]

Who are you having bore the cylinders?

 

[Aaron5555]

Not boring, just honing the cylinders and putting standard size new pistons in with new rings.

 

[mikidymac]

Did you have them checked to see if they are within spec.

 

[Aaron5555]

Used a vernier calliper to check. Its within tolerances given in the manual

 

[mikidymac]

You can't measure the bore with calipers. You need to use a bore gauge.

 

[Aaron5555]

Don't have one handy. Is there any other way to check them?
If need be the friendly neighbourhood machine shop will bore them out for me at 50 bux a pop, matched to the pistons.

 

[mikidymac]

No. Your best bet is to take them to the machine shop with the specs from the manual. They will measure and tell you if you need to bore with oversized pistons.
Don't order pistons until they measure the bore.

Also if the don't do a lot of two strokes don't let them touch your cylinders.

 

[Aaron5555]

Got it. Will have them checked after the long weekend.

 

[WKEGG]

CV Tech sell rebuild cranks for these. They are in Quebec as well. Have the same issue with mine as well. Mine is same year and motor. Can you see anything wrong with the seals that are leaking ?