99 GTI motor locked up, what now? Rebuild it or Viking Funeral?

[97SPX]

Well our GTI locked the motor up this weekend. Haven't even had a chance to tear in to it but it sounds like it starved for oil somehow. Anyway, it's locked and I'm trying to decide whether to rebuild the motor, have it rebuilt, find a used motor or just sell the carcass. I only have $900 in the whole thing so I may be better off starting over. On the other hand I like to tinker on things and I've never rebuilt a seadoo motor before, might be a fun winter project.

Any advice or suggestions?

 

[timmyboy76]

Guess you'll need to figure out, what/where, it went wrong. Dig mess'n w/ things, and needs crank assy, besides goin easy route, and replac'n w/ "sbt" engine, can find new crank assy with gaskets, pistons..etc, from ebay, 450buks shipped. But if cases are screwed, then sbt/seadoowarehouse, may be only alternative....:cheers:

 

[Nate Surveyor]

Take it partially apart. And discover what is wrong. Then, put a pencil to it.

Figure out cost to REPAIR. Cost to put new SBT in, and cost for another ski.


Then, take those numbers, and wait a little, through the winter months. Maybe you will find a crashed ski, with good motor!


Nate

 

[seadoosnipe]

Decisions.....?

:agree: with all the above. You'll need to determine what went wrong, what is the most cost effective way of repair, then go from there.

In my experience, if the motor locked up from a lack of oil, or a lost piston from detonation, then you may have hidden damage that you won't see with a bare eye. If the motor locks at high revs and you fnd a bad piston. You replace the piston and cyliinder, just to find several hours into a ride, a crank bearing lock up on you.

So, remember, if you decide to replace, do all the checks and measurements on the crank and rest of the motor for backlash, axial movement and check for any flat spots on bearing surfaces...............:cheers:

 

[97SPX]

UPDATE - Compression Test

Snipe and group,

Compression test shows 140 lbs in the rear cylinder and around 130 in the front. The motor spins fine on the starter with both plugs out. When doing the front test the starter seemed to work much harder to spin the motor against the pressure in that cylinder. Then with both plugs in the starter could barely turn the motor over one turn at a time. No where near enough momentum to actually crank.

With my limited mechanical abilities it sounds like one of the valves is not opening therefore the motor can't spin against the pressure built up in the front cylinder.

What next?

 

[kustomkarl]

If the compression is 140 and 130 psi than the difference isn't that bad. The engine is a 2 stroke and doesn't have valves. Remove the spark plugs and at the rear of the engine is a black boot with clamps on it. This boot covers the jet pump shaft. Loosen up the clamps and push the boot back. See if you can turn the engine counter clockwise by hand at the Jet pump shaft. If it is fairly easy to rotate over then your problem might be in the starter. If you can't budge it, to rotate the engine, you do need to pull the heads off to have a look inside at how bad the damage is.

In your opening post you said the "engine locked up"... did it just lock up while it was running or was it locked up when you attempted to start it up? If it was a oil problem usually the engine locks up under way and destroys itself due to lack of lubrication of the injector oil. If it just wouldn't turn over it could be the starter is bad.

Karl

 

[timmyboy76]

Snipe and group,

Compression test shows 140 lbs in the rear cylinder and around 130 in the front. The motor spins fine on the starter with both plugs out. When doing the front test the starter seemed to work much harder to spin the motor against the pressure in that cylinder. Then with both plugs in the starter could barely turn the motor over one turn at a time. No where near enough momentum to actually crank.

With my limited mechanical abilities it sounds like one of the valves is not opening therefore the motor can't spin against the pressure built up in the front cylinder.

What next?

Make sure battery has "good" juice...

 

[97SPX]

UPDATE: It's blown

I listed it on Craigslist and had a potential buyer take it to the local dealer for a quick once-over. They found a "blown crank shaft seal and it's about to throw a rod". Needless to say my potential buyer passed. I don't think this one is worth putting any more money in given the shape it's in over all. Do you think I can part it out and get around $1,000 for it? That's all I have in the whole project including the trailer. Suggestions?

Thanks to everyone for the advice.

 

[seadoosnipe]

717 motor.......?

The 717 motor is one of the easiest motors to work on. There is no counter balance shaft or RAVE system.

It sounds like your main problem is the torque on the starter. It's to weak to roll the motor.

I'd like to know how they figure it's about to throw a rod? Did they get it started or did they tear the motor down and measure end play?

Sounds like someone is trying to bait for a deal by making you feel like your ski is crap. Be careful of the one that "passed". He's likely to show back up and make an offer that's a lot less than you expected.

You can get a new OEM remanu from SBT for $750. If the ski and pump are in really good shape, it may be worth it to do the engine. Hell, if you pump a little in it to get it running, you may be able to sell it off for a profit.

Or, you can list it as is for what you got in it on ebay. Parting it out would probably bring in more than you paid. The only problem is the economy being in the trash can right now..........:cheers:

 

[fireball451]

I can't see parting out the ski if it is in really decent shape.
Don't make sense to me to kill off a good ski.
If one is real shoddy looking then fine.
Keep the nice condition ones alive!

 

[kustomkarl]

I had a friend tell me a story similar to yours with your seadoo. The buyer picked it apart and got my friend to a very low price. He came back with a offer and bought the seadoo for almost nothing. About a month later I ran into the buyer at a local watering hole. We started talking about seadoos. He was bragging about how he got such a good deal for the idiot he bought it from. After talking for few minutes I realized it was my friend's old seadoo. He sold it untouched the day after he bought it from my friend and made 2x the money he paid. Some people have no hart...just $$$ in their eyes. I never let on I new the previous owner...till he was finished with his story. He just said" gotta run", and left.

Karl

 

[97SPX]

I agree but this one's pretty rough. If it was prestine I'd spend the money on a motor. Like I said I've only got $900 in the whole thing anyway including the trailer so I'll probably part it until I get that amount then give away the carcass.

If this buyer tries to lowball me when he returns it I'll just tell him I won't take less than that and that I'm going to part it.