2001 GTXdi top end rebuild

[tflessner]

I did a top end rebuild on my GTXdi last year and have been meaning to post a few pics. I did the Fullbore.com rebuild kit with the Pro-X pistons. So far so good, with about 10-15 hours on the rebuild......

Took the Rave valves out to look into the cylinders. The front piston had basically no compression. This pic I have the fuel injection rail off also.

Starting to tear apart. Took the exhaust off.

By the way, one of these wrenches sure does help when taking off that one bolt/nut on the bottom of the exhaust. I ground some extra metal off the edge to make it fit even better!

Head is off, ready to take the cylinders off.

 

[tflessner]

So, got the cylinders off.......can you see the problem?

Maybe a closer look will show things better. Yeah, the engine doesn't run so well when the piston looks like this!!! And part of the top ring was missing. There were a couple small pieces in the bottom case, which I got out.

Taking off the pistons off here. Make sure none of the needle bearings fall down into the crank case!! That wouldn't be good.

My Fullbore kit arrives!!!!

 

[tflessner]

Re-assembly

Ok, got the Pro-X pistons on.

Cylinders on. I used a couple large hose clamps to compress the rings on the pistons until they slid up into the cylinders. I should have taken a picture of that!

The head is back on.

Exhaust is all back on, with hoses, etc. hooked up. (again, that fancy wrench came in handy!)

 

[RebuiltSeadooBaffles]

So what caused the ring to break? How many hours are on the motor?

 

[tflessner]

Well.....It's all back together, now is the scary part, seeing if it will start!!! .......and run without falling apart!

IT DID! And here it is on the lake this year to prove it, along with the RX.

It did need a new fuel pump after that also.......that may be a different post sometime. There are some good posts on this forum regarding the aftermarket fuel pump installations, which is what I did.

I downloaded a service manual to follow as I re-assembled everything, following the proper torque settings, etc.

Just thought I would share, and post some pics.

 

[tflessner]

The ski has approx. 249 hours (I'll have to check for sure?) It had about 234 when I got it. I bought it from the previous owner with the bad engine.

 

[SabrToothSqrl]

Good photos. I don't want to sound negative; but I hope the crank doesn't give you any issues.

 

[tflessner]

Good photos. I don't want to sound negative; but I hope the crank doesn't give you any issues.

I agree, I took a bigger risk on this machine just doing the top-end. But we don't put that many hours on it each year, and it was bought to be a less expensive machine that we could possibly take to Lake Powell. Carb 2-strokes are prohibited now on Lake Powell.

 

[DooWacka]

Great post and pics! Thanks!

I have done this also on my 2001 GTX DI. However, I didn't take the exhaust off, so some of the bolts linking the exhaust to the cylinders were a little hard.

1) So, is removing the portion of the tuned pipe very difficult, and is it worth the easier access to the cylinder exhaust port bolts?

2) How in the world did you get the small ring pieces out of the case?

3) Did you get an assessment from FullBore as to the cause, or do you know what the cause may be for the melted piston? I was thinking my cause was very long runs at WOT on particularly smooth water.

4) What compression do you have on the new rebuild, and after your 15 hour break-in? I know that Colorado altitude will cause less on the compression test than at sea level, but how much less?

Thanks again for the great post!

 

[tflessner]

Great post and pics! Thanks!

I have done this also on my 2001 GTX DI. However, I didn't take the exhaust off, so some of the bolts linking the exhaust to the cylinders were a little hard.

1) So, is removing the portion of the tuned pipe very difficult, and is it worth the easier access to the cylinder exhaust port bolts?

2) How in the world did you get the small ring pieces out of the case?

3) Did you get an assessment from FullBore as to the cause, or do you know what the cause may be for the melted piston? I was thinking my cause was very long runs at WOT on particularly smooth water.

4) What compression do you have on the new rebuild, and after your 15 hour break-in? I know that Colorado altitude will cause less on the compression test than at sea level, but how much less?

Thanks again for the great post!

Thanks DooWacka, I've been meaning to post these for awhile, but never get around to it. I did an engine replacement on a 2000 GTX carb model last year also, with the rebuild done by SES. So far, so good on that machine also. My next project is a 2002 RXdi, after I get done with a '96 GTI with the 720 motor. Guess I've turned into a Seadoo mechanic?

I'll answer your questions as much as I can remember, since it's been a year on that project.

1) I removed as much of the exhaust to make it the easiest to work on. The Fullbore.com kit came with the gasket kit, and I took the exhaust all apart to put the gaskets on. The only bolt/nut that was a pain was the one directly under the black pipe (you can see it in the second picture). Needed that special wrench. The rest of the bolts were all fairly easy to get off.

2) I used a magnet and some extra long needle nose pliers. There wasn't much down there since I think some went out the exhaust?

3) I didn't think about sending the pistons to Fullbore. Wish I had done that. I just assumed it was the age/hours of the machine, and as you said, possibly some long runs at WOT.

4) I haven't check the compression yet. I've been meaning to do that, and will report back when I do.

 

[lamajama]

Well.....It's all back together, now is the scary part, seeing if it will start!!! .......and run without falling apart!

IT DID! And here it is on the lake this year to prove it, along with the RX.

It did need a new fuel pump after that also.......that may be a different post sometime. There are some good posts on this forum regarding the aftermarket fuel pump installations, which is what I did.

I downloaded a service manual to follow as I re-assembled everything, following the proper torque settings, etc.

Just thought I would share, and post some pics.

Great post! I see that you used the aftermarket fuel pump - can you comment on the installation re: tips etc in installing it?

Doowacka has that excellent post on rigging the aftermarket pump. :thumbsup:

Also, please keep us informed as to the performance of the fuel pump. More of us are using this non-OEM and it's great our
"in-water testing" is getting more extensive. I have one but it's a back-up ready for the (knock-on-wood) eventual need!