1997 GTX - Power loss after initial acceleration

[djsexton68]

Hi everyone! First I would like to say that those of you who I have viewed briefly on other troubleshooting Thread's are incredible, especially KustomKarl. The help and suggestions you offer is priceless to guys like me who really don't have clue and continually get beat up by Service Departments who often under evaluate, over charge and take forever!

I just bought a couple of really clean - 175 hour 1997 GTX's to get my family (15 & 12 year old) back into PWC's. I had such a bad experience with my 1996 XP that I purchased new and after only 8 months, I sold both it and my Kawasaki 750 and gave up on the sport!

Then I go yesterday and buy the same damn engine as my 96 XP in the GTX's, possible stupidity and here I go again.

The machines are impeccable and idled and accelaerated perfect on the trailer at inspection. I put them on the water tonite and one of them started out fine but as we drove them from the ramp over to our home dock, it kept kept losing more and more power. To the point that everytime I gave it throttle it would ty to plane and then almost stall out. I thought that it might be a loaded up spark plug, but to my dismay, they were both brand spanking new NGK BR8E's.

After reading other threads I have a couple direct questions:

1. Any thoughts on why this power loss is happening?
2. How, where and for how much can I buy that compression testing tool that was referred to on other GTX threads?

Thanks for any input in advance and sorry for being so long winded, but it sucks to have your kids look at you like you just bought a dud that they can row faster than!

 

[josh42575]

autozone has compression testers for pretty cheap. not the most perfectly accurate but theyll get you pretty close for cheap...

 

[djsexton68]

Thanks for your help.

These AutoZone testers will fit the standard cylinder head threads of my ski or are there multiple sizes based on current spark plug size (ie-BR8ES)

 

[Skatman]

Water regulator.....

On the 787, you have a water regulator that injects cooling into your tuned pipe assembly. If this is stopped up, it can cause the problems you are having. Also, the RAVE can cause this problem.
Look on the back of the resonator, in your exhaust system. You'll see a round thing with a black plastic cap. Take loose those two hoses, remember which hose goes where, and unscrew it. There is a small brass piece between the resontor and the black casing that usually gets stopped up with a piece of sand, etc......make sure that brass piece is clear. Also, the short hose, maybe 2 inches in lengh should be o.k., but he one you see going down and under the engine, that runs up to your tuned exhast at the cooling water inlet. Right by that big hose that goes into the exhaust. That elbow should have the number 22 stamped on it. That's because it too, has a specific "orifice" type design to allow a precise amount of water to work right. If this system is not working, you can do serious engine damage and also, loose performance as you've stated.
The other reason would be dirty guillotine valves of the RAVE.

 

[djsexton68]

Thanks Skatman!

I'll print out your response and take it down to the dock and start the process of elimination. Thanks again!

 

[scooper77515]

Running hot?

 

[djsexton68]

No. It seems fine but I didn't really have a chance to get it too hot. What is the normal temp it should run at? I'll test it and get the exact digital number. Thanks, Dale

 

[djsexton68]

Took apart the water regulator and cleaned it up, removed the RAVE's and cleaned them as well, made sure the fuel filter was not clogged up and and then changed the spark plugs.

Same results!!!

When we checked the fuel filter we drained some fuel and it was very, very thick and it seemed it was way to rich. Almost like there was more oil than gas. How do you adjust the oil injection? We made sure we put the correct two cycle oil in as it stated on the side of the oil resevoir cap.

Any thoughts? Thanks, Dale.

 

[robin savell lloyd]

It sounds like someone has been premixing if you found oil in gas. are you sure it has not been changed over to premix? the way you describe it loosing power sounds like a leaning condition if this is so and you keep riding you will notice the compression will get lower each time you ride.I am no expert I can only share with you my opinions. :cheers:

 

[djsexton68]

I just called the previous owner an he told me that he did not pre-mix. He stated he had a similar problem on one of his other jets skis and he simply had the small filter (screen) in his carbs cleaned and it took care of the problem.

I guess I'll try that tomorrow. Any ideas or I am still just guessing?

 

[robin savell lloyd]

:agree: with previous owner this will cause a lean condition I hope this solves your problem. :cheers: If you have gray fuel lines replace them as they are defective and break down and clog filters in carbs.

 

[derek]

grey fuel lines? get rid of em. the insides dissolve into your fuel. gum up carbs. if they aren't the prob now, they will be. it sounds like lack of fuel flow. at idle the carbs fill up. then they give you just enough gas for enough throttle to start to climb out of the hole. then carbs run dry. boat sputters back to idle.

 

[djsexton68]

You guys rock! I'll let you know tomorrow. Thanks again.

 

[djsexton68]

I just purchased and downloaded the Service Manual. It should help. If anyone needs any info from it let me know.

 

[kustomkarl]

Hey Dale, I just read the post on the forum about your problem...With all that you tried with the exhaust Valve( round item with the hoses by the exhaust pipe), And cleaning the RAVE valve(Rotax Adjustable Variable Exhaust). should have helped. and it needed it anyway so it wasn't wasted labor. Your model just might have a "gray hose" problem and allowed gunk in the carbs.The manual will help you with the clean up...We have a "Premium Member" section on this site so you can download a authentic seadoo manual and read it on line as a pdf or print off if needed. Click on the "Seadoo Manuals" link at the top of page for details.

As far as the problem, I would dump the fuel and start fresh. Did the last owner add anything to it if it wasn't used for a while? Pull the carbs and clean them up. Pay special attention to the small filters inside as they clog real easy. I would do a compression test also so you know what is going inside and not be guessing. Compression should be ideally 150 psi per cylinder. If you need help with the compression test let us know and we'll point you in the right direction. Let me know how you make out and keep us posted.

Karl

 

[djsexton68]

Thanks Karl. I bought a Compression Tester yesterday as recommended and will perform that test when I get them back running. Took off the Black Carb cover, the stainless wire mesh filter and everything to get to the carbs themselves. The problem is...I don't know how to get the carbs off to get to these filters inside them. I will search for a picture diagram or how to picture show explaining the procedure but I am officially stuck. I assume I will have to dis-assemble the throttle cable and choke cables to perform this procedure, but i stopped dead in my tracks until i could get back online and into the Forum.

Any links or directions that can help?

Thanks, Dale.

 

[robin savell lloyd]

Take your time if you need to take photos as you take it apart. It is hard to mess things up. all you have to do is clean filters and put it back the way you found it. If this is your first time I am sure you can be nervous but take your time and it will work out.

 

[kustomkarl]

Dale, we could converse about the carbs in the forum till the cows come home, but I think you should join as a "premium Member" to help you get your problem repaired. As a premium member you can down load a authentic seadoo manual from the seadoo manual library. In the library is a variety of manuals for almost makes and models. You can view as many as you like on line as a PDF file, or download it and print it for your personal and privet use. There are operator manuals and repair manuals for you to do your own repairs on your seadoo. The repair manuals have everything from troubleshooting, repair procedures to winterizing. It contains wire diagrams torque specs and pictures for disassemble and assemble instructions. In the spec sheets it tells everything needed to maintain oil changes, spark plug gaps, impeller wear ring tolerances and carburetor rebuilds. Click on the "Seadoo Manuals" link at the top of the page for more details. If you need any help or get in a jam, we are always here to answer your questions too. I think this is a smart way to go, so you have information first hand.

Karl

 

[djsexton68]

Thanks everyone for all of your help. It appears at this point I am in over my head. I took off the Carbs on one of the them, finally got to the little filter which was severally full of black flaky pieces and put it back together. SAME RESULTS on the water test.

Can any recommend a good private repair shop or individual in or around the Sarasota \ Bradenton area or a Dealer who you trust?

Thanks, Dale.

 

[kustomkarl]

Dale, PM sent...