1996 Seadoo XP runs on land????

[fcards]

This one may be a little odd.....It seems odd to me.

I have a 1996 Seadoo XP. I've owned it since 1998. I bought it with a blown motor and had the motor replaced by a dealer. It ran great up until 3 years ago.

Three years ago, it would run, but then die at WOT. It was difficult to start after that. I've taken it to another dealer (original dealer retired ). I've spent $1000 and 2 trips to the dealer only to find out he has no clue. The first time I took it in, he replaced a "sensor on the flywheel" and charged me $600. The second time I took it in, I told him he hadn't fixed it yet, he told me that I needed a rebuild and adjusted the throttle plates because they weren't sychronized ($400 later).

I've rebuilt the engine even though I know that the motor should run and start in the water. A rebuild wasn't going to fix my problem.

So that brings me to today... I'm able to start the motor on land with no trouble. As soon as I put the machine in the water, I can't start the motor. I've even started the motor on land and backed it into the water, and it will run. If I shut it down and quickly restart it will start. If I shut it down and wait 10 minutes, it won't start. I'm frustrated....and I have no confidence in the dealer.

Sorry for the long and drawn out story, but I'm trying to give all the facts.

Any ideas would be appreciated.
Thanks.

 

[Jeff Walkowiak]

Re: 1996 Seadoo XP runs on land????

I guess it is a 787, we first must know the compression for each cylinder, not starting in the water usually indicates low compression on one cylinder, start there oh did I tell you I hate 787 engines lol but I also hate 951 engines more.:|

 

[fcards]

Re: 1996 Seadoo XP runs on land????

Thanks Jeff, I'll check tonight and let you know.

 

[Jeff Walkowiak]

Re: 1996 Seadoo XP runs on land????

those love to snag rings on the raves, running fine and pow stops without warning, when you try to restart it you get a funny sound while it turns and sometimes a backfire in the exhaust

 

[fcards]

Re: 1996 Seadoo XP runs on land????

That sounds awfully familiar. I've noticed the backfiring and the last time I rode it, it just stopped. I only have about a half hour on the rebuilt motor.

 

[fcards]

Re: 1996 Seadoo XP runs on land????

Jeff,

Yes it is a 787......and yes there is a discrepancy between the 2 cylinders. The front one (front of the machine) reads 132psi and the back one reads 60psi. I never remember which is the PTO or which is the Mag side.

Any suggestions short of tearing it down and checking it out??

Thanks.

 

[Jeff Walkowiak]

Re: 1996 Seadoo XP runs on land????

there is the problem, remove the rave valve and have a look at the rings through the rave opening but I already know you snagged a ring and there is your lack of compression. did you do the rebuild and did you clean the raves real good? and if you did the rebuild you put the pistons in facing the correct direction??

 

[fcards]

Re: 1996 Seadoo XP runs on land????

Jeff,

I'll look tonight.

When you say that I've "snagged a ring", what do you mean? Will a ring be broken (cracked)? Can it be fixed?

Yes my brother-in-law and I rebuilt the motor. We put the pistons in with the arrow point to the exhaust side. I cleaned the raves before putting it back together.

At this point, assuming that I've snagged a ring, how do I fix it and prevent it from happening again?

Thank you very much for all of your help. I can't believe that the dealer couldn't figure this out.

Thanks.

 

[Jeff Walkowiak]

Re: 1996 Seadoo XP runs on land????

It depends on the condition of the piston and rings if this happened you will need to remove the jug piston etc I even tried taking a little off the raves to stop this but it still happened, if you bored the cylinders the raves may be going in too far, I had the same thing happen several times,

 

[fcards]

Re: 1996 Seadoo XP runs on land????

Thanks Jeff,

I'll check it out and I'll let you know what I find.

 

[fcards]

Re: 1996 Seadoo XP runs on land????

Jeff,

I haven't had time to look at my machine. I'll be looking at it next week. I really appreciate what you've done so far. I finally feel that there might be a resolution.

Btw, if I find that the rings are being snagged, do I need to replace the sleeve? I didn't bore the sleeve when I did the rebuild, I only had it honed to clean it up. The problem of stopping in the water started before the rebuild when I took it to the dealer. So I'm assuming I must have clipped a ring before the rebuild. I had scoring in the cylinder hence the reason for the honing.

I'll talk to you next week, after I take the engine apart.

Thanks again,
Frank.

 

[Jeff Walkowiak]

Re: 1996 Seadoo XP runs on land????

I guess you may have more ring gap that you should, perhaps the cylinder is out of round, any number of things could be the problem but since it did it so soon I would honestly suspect that you did not do something correct when you did the engine, I would suggest pulling both jugs and have them miked etc at a machine shop, they probably need to be bored and go to oversize pistons but be sure to have the raves cut to match.

 

[Jeff Walkowiak]

Re: 1996 Seadoo XP runs on land????

other issues with those engines ,, you need to do a straight edge across the top of the jugs when you tighten them because they are seperate jugs I have seen one sit lower than the other and since the head is a single head it can cause problems with the seating of the o ring, also there is a plate that must be attached to the jugs before you tighten them to be sure they are alighned properly for the exhaust manifold to seat against them correctly or water can leak in to the combustion chamber and toast the rings.

 

[fcards]

Re: 1996 Seadoo XP runs on land????

Thanks Jeff.

I'll be sure to look at that stuff.

Frank

 

[sloopy]

Re: 1996 Seadoo XP runs on land????

I hate those little two stroke Rotax engines as well. If it makes you feel any better they use a de-tuned version of that engine on some experimental and ultralite aircraft, it is pretty much the same block but with less stroke. :/:/:/

What ever you do DO NOT go back to your mechanic, I honestly can not see spending 500 to fix something on the flywheel, especially when you could probably of purchased the flywheel and what ever attaches to it for under 400.

Jeff is right (as always) about the rings. BTw with the rotax engines you are much better off having a machine shop or purchasing new, if you hone yourself you may not get the clearance needed for these engines, they tend to be finicky about that, which is there downfall. It may also explain why your ring was catching.

Jeff may know the truth of this (I don't) but I have heard through the grapevine that if you install one of the rings upside down you will have the problems jeff described. Apparently they are tapered or something, but I don't know the truth of this maybe jeff can confirm it.

 

[sloopy]

Re: 1996 Seadoo XP runs on land????

"he second time I took it in, I told him he hadn't fixed it yet, he told me that I needed a rebuild and adjusted the throttle plates because they weren't sychronized"


Find a new dealer.

 

[Jeff Walkowiak]

Re: 1996 Seadoo XP runs on land????

on the rings the top one from the factory is a keystone ring and it would take a total moron to put it in upside down. some aftermarket pistons don't use keystone rings and that may be a good thing because keystone rings are more prone to snagging, if carbon builds in the taper it can push the ring out over a port and catch the edge,it only takes one time for some carbon to get in the ring and kiss it goodbye.
as for the carbs synking them is imoprtant and on those engines it is a lot more difficult to do because there is no plate , they must be done on the engine and it is hard to see when you are doing it, plus they use a tie rod with play in the ends.

 

[sloopy]

Re: 1996 Seadoo XP runs on land????

It is possible they could of been upside down, I'll admit I have done it, but never ever on a rotax engine.
Call me a moron (join the club) if you must but 400 is to much to sync the carbs, that should take two hours tops.

 

[Jeff Walkowiak]

Re: 1996 Seadoo XP runs on land????

about 45 min, you remove the air box and filter , un adjust the idle stop screw , count how many times you turn the screw so you know where to put it when you are finished, un hook the throttle cable or be sure it is loose so it isn't holding the carb from going all the way closed, pop off the tie rod from the front carb to the back carb. look down the carbs to see the bottom plates are both the same totally closed . the tie rod is left hand on one end and right hand thread on the other end so you un lock the 8mm nuts that hold the threaded piece from turning and adjust the rod so it is just at the point of opening the back carb when you touch the lever on the front carb being sure there is no slack in the ball joint ends, lock the 8mm nuts to keep that setting and turn your stop screw back to where it was I usually use 5 turns that is more than enouigh to clear the stop. then adjust your throttle cable where it opens the bottom of each carb at w o t perfectly straight , once you go past straight it starts to close up the opening, there should be some slack in the cable but just a small amount. when the throttle lever is released the 2 carb plates should be equal . then put the air box etc back on. I use a mirror to look down the carbs because of the angle they are at with the engine sitting in the ski.
after you finish it is a good idea to use the mirror and double check the timing notch on your oil pump as all the carb adjusting may have changed it slightly.

 

[sloopy]

Re: 1996 Seadoo XP runs on land????

WOULD YOU PAY 400 FOR THAT WORK?

I know how it is done jeff . except I use calipers, and a ruler to make sure the plates are in the same location ( I measure from the tip of the plate to the wall, it should be the same as the others ). But then again I have never done it on any of the rotax engines, only Yamaha and Kawasaki skis.



All this is not really helping the guy, it will not bring his PWC back to life, sorry fcards