1996 GTX Up and Dies

[Rob Dog]

Please read to end prior to replying....

I have been chasing an issue with our 96 GTX 787 for a couple of years. Here is the background.

A couple of years ago I was riding it for about 5 - 10 minutes and it all of a sudden lost power. It did not die. I idled it back to shore and that was it. I rebuilt the carbs and it still would not run.

This Spring I found a local guy that still works on old model SeaDoo's. He rebuilt the carbs again with a Mikuni OEM kit. He set the low end to 1 1/2 turns on both and zero on the others. He sent a video to me showing it running and said "good smoke" It was revving well. When I picked it up he told me that he had drained the fuel and put in premix.

We took it to the lake and ran it. It had trouble getting "out of the hole" but top end was GREAT. The next day I let the mechanic know what was going on and he backed off the low end a 1/4 turn each. Next time out was a lot better. The ski was blowing smoke but seemed pretty normal.

Now the fun starts.... he then said I could run straight ethanol free premium. So I drained the tank and filled it with straight premium.

My wife got on the ski and made a lap around the lake and then she lost power. Just like the original problem. No it will start but will not go more than 2800 RPM. When I got the ski home I started it in my shop and noticed NO smoke. I shut it down. My thought is that the engine is not getting enough oil and it is getting hot then shutting down. I am NOT sure if there is a sensor for that, but that is how it is acting.

There are a lot of posts here saying not to run pre-mix but it seems like that is the main thing that changed. I just pulled the carbs and made sure the low end adjustments are at 1 3/8 turns and it starts and revs fine now. I do not want to run it until I get some feedback.....

I am under the impression that running a little too much oil would be a lot better than running with no oil... If you are still reading THANK YOU in advance!!

 

[mikidymac]

You first need to verify you still have the oil injection system, if not your engine would have already seized.
You should have an oil tank, a oil pump on the front of the engine next to the gas tank and small hoses going back under the carbs. The only thing that fails on these is the small oil lines from the oil pump to the intake manifold, if they are covered in white paint they are original and should be changed.

Report back what you find.

 

[Rob Dog]

I defiantly have the oil system and the oil lines are white! I will replace them!! This photo shows them and some oil in the bilge. Maybe related?

Once replaced, how do I know that oil is getting into the intake manifold other than watching for smoke in the exhaust?

 

[jchance]

You can leave a SMALL air bubble in the lines and watch for it moving. I do this after a rebuild BUT I am also adding Amsol Interceptor to the gas for break-in.

 

[burtshaver2021]

There is also a test layer out in the manual where you can test the oil pump. I call it good if I put the new oil lines and watch the oil pulse through the new lines as I’m holding the oil lever wide open. I will also run premix on a new to me machine till I’m sure the oil pump is working, not needed though

 

[Rob Dog]

I am thinking of connecting the new tubes to the pump and then starting it. Should I be able to see oil getting pumped through the new lines?

 

[burtshaver2021]

If you are using genuine OEM oil lines from BRP you will be able to see the oil filling up the.lines, not sure about Tygon, I’ve never used it.

 

[mikidymac]

I am thinking of connecting the new tubes to the pump and then starting it. Should I be able to see oil getting pumped through the new lines?

These skis are under no load at idle out of the water so they require basically no oil to be perfectly fine. As long as it isn't a fresh rebuilt engine there will be enough residual oil in the crankcase for engine lubrication. Whenever I prime an oil system I hold the oil pump lever wide open and start the ski and let it diel. You will see ie very quickly pumping oil into the lines and when it gets to the intake and starts smoking you are good to go. The engine idling at 3,000 rpm will prime much faster than a drill.

 

[Rob Dog]

These skis are under no load at idle out of the water so they require basically no oil to be perfectly fine. As long as it isn't a fresh rebuilt engine there will be enough residual oil in the crankcase for engine lubrication. Whenever I prime an oil system I hold the oil pump lever wide open and start the ski and let it diel. You will see ie very quickly pumping oil into the lines and when it gets to the intake and starts smoking you are good to go. The engine idling at 3,000 rpm will prime much faster than a drill.

I just saw this reply... Thanks! But before I saw it, this morning I replaced the two little oil lines from the oil pump to the intake manifold and then started it. I let it idle and as you said, nothing happened except about 1/2" up the line. I revved it a few times and no change. I figured the pump is shot so I put pre-mix in the tank and we were headed to the lake to test. Then I saw your note.. CRAP!! I think I will run it with the premix in it just because when I got it back from repair that's what it had and it ran great. When I drained the premix and went to straight gas the problem came back. I will post later tonight on how today goes. Thanks again!!!

UPDATE...... Just returned from the lake and she ran GREAT. No excess smoke and it was fast. The only interesting thing that happened is that the OIL light came on. Tells me that, yes, it is pumping oil. So if it is pumping and I have 40:1 premix, what would you recommend I do. Ease into no premix, dump all the premix or stay with what appears to be working? I value your opinion!

 

[burtshaver2021]

Now the fun starts.... he then said I could run straight ethanol free premium. So I drained the tank and filled it with straight premium.

My wife got on the ski and made a lap around the lake and then she lost power. Just like the original problem

If this was the case and the oil pump wasn’t working while you were running straight gas it wouldn’t be running anymore.

 

[Rob Dog]

If this was the case and the oil pump wasn’t working while you were running straight gas it wouldn’t be running anymore.

Thanks for the help. I sent this reply to MIKIDYMAC:
I just saw this reply... Thanks! But before I saw it, this morning I replaced the two little oil lines from the oil pump to the intake manifold and then started it. I let it idle and as you said, nothing happened except about 1/2" up the line. I revved it a few times and no change. I figured the pump is shot so I put pre-mix in the tank and we were headed to the lake to test. Then I saw your note.. CRAP!! I think I will run it with the premix in it just because when I got it back from repair that's what it had and it ran great. When I drained the premix and went to straight gas the problem came back. I will post later tonight on how today goes. Thanks again!!!

UPDATE...... Just returned from the lake and she ran GREAT. No excess smoke and it was fast. The only interesting thing that happened is that the OIL light came on. Tells me that, yes, it is pumping oil. So if it is pumping and I have 40:1 premix, what would you recommend I do. Ease into no premix, dump all the premix or stay with what appears to be working? I value your opinion!

 

[burtshaver2021]

A couple of things come to mind. One of which is you said you let the machine idle with new small oil lines? Did I read that correctly? If so, they barely pump any oil at idle, when your filling up the new small oil lines, you reach down and lift the oil lever manually so that the oil pump is pumping max oil flow while the ski is only idling. The new lines should fill up with oil in about 3 or 4 seconds. I would be interested to see what your compression is, if in fact your oil pump is not working, which I have never seen before, but there will eventually be a first time, the. I would think when your wife was riding it on the lake it would have destroyed itself with no oil, leads me to believe that the oil pump probably is working correctly and there is another issue. With that being said I would stick with your pre mix until you are positive the pump is working or is not working. Also see if the ski stops working after 10 minutes as it did before. You can’t do any harm by pre mixing even if the oil injection is working. Mark the oil tank with a sharpie while the machine is on the water so you know its level and see if it goes down. This isn’t an absolute fool proof method by any means since your machine could also use a bit of oil if the inner crank seals are leaking as well. If it were mine and I wanted to know if the oil injection was working I would probably change those small oil lines again just so I could look and see if the oil pulsed through them and filled them up. You could also bench test the oil pump, but I’ve never done that, so no help there. There is a procedure in the manual though. Have you noticed if your getting water coming from the pisser while driving? Does the wear ring look good? Any chance it’s over heating? The oil light coming on does not mean the oil pump is working, that light only means your tank is low on oil or the float is defective.

 

[Rob Dog]

A couple of things come to mind. One of which is you said you let the machine idle with new small oil lines? Did I read that correctly? If so, they barely pump any oil at idle, when your filling up the new small oil lines, you reach down and lift the oil lever manually so that the oil pump is pumping max oil flow while the ski is only idling. The new lines should fill up with oil in about 3 or 4 seconds. I would be interested to see what your compression is, if in fact your oil pump is not working, which I have never seen before, but there will eventually be a first time, the. I would think when your wife was riding it on the lake it would have destroyed itself with no oil, leads me to believe that the oil pump probably is working correctly and there is another issue. With that being said I would stick with your pre mix until you are positive the pump is working or is not working. Also see if the ski stops working after 10 minutes as it did before. You can’t do any harm by pre mixing even if the oil injection is working. Mark the oil tank with a sharpie while the machine is on the water so you know its level and see if it goes down. This isn’t an absolute fool proof method by any means since your machine could also use a bit of oil if the inner crank seals are leaking as well. If it were mine and I wanted to know if the oil injection was working I would probably change those small oil lines again just so I could look and see if the oil pulsed through them and filled them up. You could also bench test the oil pump, but I’ve never done that, so no help there. There is a procedure in the manual though. Have you noticed if your getting water coming from the pisser while driving? Does the wear ring look good? Any chance it’s over heating? The oil light coming on does not mean the oil pump is working, that light only means your tank is low on oil or the float is defective.

Thank you again for the help!! After I installed the new lines this morning, I started it and some oil came into the lines. About 1/2". I revved it a few times and it did not change. I then decided to put premix in. THEN I checked these posts and saw about manually pulling the lever. I started it again and at idle pulled the lever and sure enough oil started moving up the lines and in about 5 seconds reached the manifold. When I had it worked on, the guy tested the compression and it was good! I will mark the tank see what happens. There is some oil in the bilge. Not sure where it is coming from. Wont be able to test again until next week. Headed to SoCal for a wedding. I am in OR..... Not many warm days left. Thx!!