'99 GTX LTD (951) won't run 7K in the water

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SabrToothSqrl

SabrToothSqrl

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Have a 1999 GTX LTD, rebuilt engine last summer, ran fine from then till now.
Put in a new impeller (factory) and wear ring last fall...

Won't break 6,200 RPM on the water (will on land).

Ran 58 MPH start of season, now around 52.

I pulled and cleaned the RAVEs.
I Pulled the water regulator from my other ski.
I replaced the air lines and check valve off the crank case (valve was letting air go both ways, one line was cracked open)
I replaced the entire fuel filter assembly
I took out and cleaned out the fuel selector switch.
I replaced all the fuel lines with new, minus the ones actually ON the carbs.

I have been bashing my head against the wall on this for almost 2 weeks now.

What's left to test / fix / change?!

The only thing I can think of is there are filters on the carbs right? If I pull the carbs, maybe I will find my answer? a seal, or a filter issue?

The engine seems to run fine, starts fine, just not 100% power and I am 800 RPM shy of where it should be...

Suggestions / Help / Padded wall?

thanks!
 
lines

I plan to replace the remaining few inches of fuel line this fall when I pull the carbs...

But any other suggestions or can I just wait till fall and actually enjoy my jet ski for the rest of the season, even if it lost 800 RPM.

Ohh, and yes, it passes the compression test. Also new plugs, and I did the cut the plug wires back 1/4" thing as well.
 
when you installed the wear ring and impellor, last fall, is now the first time having it out, and noticed the 6200rpm?
 
I've been watching your posts as I have a '98 GTX Ltd that runs exactly the same as yours.

I installed a new impeller and wear ring this spring (rebuild from Impros), but it only turns 6100 rpm in the water and tops out at about 54mph.

I feel a little better letting my daughters take it out knowing that 54 is plenty fast enough for them. The majority of the time the ski is used to pull tubes, so it's not run wide open anyway.

I say try to enjoy that it runs as good as it does for a few weeks and quit staring at the gauges. It's no fun to continuously work on the same thing!
 
No

It ran 7000 and 58-60MPH this spring. With the new impeller and wear ring. They are factory parts. I didnt change the pitch or size / etc.

Now it runs 52 MPH and 6,200 RPM and doesn't feel like it's pulling as fast as it should because when you floor it, it only hits 6,000 on launch, not 7,000.

Carbs are my next area to attack, but I'm just so sick of working on it and not getting anywhere...
 
ok, so out of nowhere, it lost, about 700 rpm.

check for blockage in the cooling system...W.R. lines. Make sure the raves are opening, can run the ski without seat on and caps removewd to verify that.
 
Join the club. Mine hit 6800 rpm at the beginning of the year and I'm clocking about 6200 RPM. Kinda feels like a govenor? Doesn't spit or sputter. Real fast getting there, but once it gets there, that's it? Is yours an SBT motor? Ive done all the things you've done, except, I have put new filters inside the carb. 54 mph is fine with me its my wifes ski. She only goes 45 mph anyway.:cheers:
 
yea

Correct, seemingly from no where it lost 800RPM.

I will check the water hoses tonight; but I'm fairly sure that's not it.

It's not a SBT block, but it was a new one, it's bronze in color while the rest of the engine is a grey.

This is the wife's as well, (I have an '02 XP that's WAY more fun) but we use it to ski as well, and I need the get up and go of 7,000 RPM... and need to know running under that won't damage anything.

I have been over the RAVEs now 4 times, i can pull the tube, blow in and they open up just fine, I cleaned out all the gunk that built up over 11 years of not cleaning them... I also took apart the water pressure regulator, found it to be in 100% shape, but swapped it with my XP, and no difference, so I swapped those back...

My wear ring and impeller came from a bust sea-doo dealer, got a good price on them, all factory parts :)
 
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the raves work off the solenoid, mounted to side of hull. See ifyou can find t-barb(homedepot garden section/irrigation system), and bypass the solenoid, take tube from down under motor, going to solenoid, and go directly to the fittings on rave housing.
 
right

Correct, and I have even jumped that selenoid right from the battery, every time i get a solid click like it's engaging / disenguaging. I can check it again tonight by blowing in it...

but I would think that if it wasnt allowing air in (from the crank case) that it wouldn't get any where near 6,200 RPM.

I replaced the check valve as well that goes from the crank to that selenoid.

after the selenoid, it splits to each cylinder, so u can just attach it there

which would effectively mean the RAVEs are open all (or most) of the time.

When I hit 4500 however it does give the kick of that solenoid opening, because I feel the jump in power where it jumps from 4500 to 5500ish RPM as they open...
 
typed at same time....

did u switch the W.R. with your xp? Clear out the fitting at pipe and at muffler, where it connects to?
 
yes

Yes, even after inspecting the water reg (which is 100%) I swapped it for the one from the XP. No Change :mad:.

the air lines AND part #26 (check valve) are all new, installed last night.
 
cooling lines

even though I don't think they are at fault, if I wanted to replace the cooling lines, how much do i need?

I assume heater hose works fine:

1/4" , 5/16" and 1/2" from what I can see, but not sure how long of each...

And it will do 7,200 on the trailer (out of water) so it's not being limited by anything electronic. Just not enough UMPH to pump at 7K.

Shop manual says to replace oil filter annually!!! Mine is 11 years old... Although I don't think it's the problem, and I've only ever run sea-doo XPS-II or whatever the best stuff is, for $10, I'll get one for each ski...
 
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pump

the pump on my XP is way different, it's all aftermarket stuff (came with it) I don't want to take it apart... but I will take the GTX one apart and give it a looking over I guess... but not today... today, we ride!
 
pump

we are talking the jet pump right?

Both my GTX and XP have the same (947) engine...

I kinda planned it that way :) The biggest 2 stroke sea-doo makes... less complicated than the 4s... but maybe in a few years I can afford some new ones...
 
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Subscribed. EXACTLY the same problem on a 98 GSXl. Rebuilt carbs, all new fuel lines, selector valve, cleaned baffel, everything in the fuel circuit is new. Cleaned the raves and they seem to function fine. Water regulator doesn't leak. I will send someone money if they can figure out whats causing this! There are a lot of people on forums around that seem to have this problem! ive been researching it alot and I even have the service department at my dealer stumped.
 
I have a 97 gtx that is doing the same thing. Nail it and it goes to 5000 and sit there running smooth. If you let off throttle and nail it ( and do this 3 or 4 times.) it will go to around 6800 and run fine. If you let it get down past 3000 or 3500 and nail it it won't go past 5000. New SBT motor. Plugs look fine. Rebuilt and adjusted carbs. Found broken spring in WPR and replace with no results. I'm with the guy that will pay somebody to help get this fixed. Somebody please help!!! Thanks
 
STUNNER17 said:
I have a 97 gtx that is doing the same thing. Nail it and it goes to 5000 and sit there running smooth. If you let off throttle and nail it ( and do this 3 or 4 times.) it will go to around 6800 and run fine. If you let it get down past 3000 or 3500 and nail it it won't go past 5000. New SBT motor. Plugs look fine. Rebuilt and adjusted carbs. Found broken spring in WPR and replace with no results. I'm with the guy that will pay somebody to help get this fixed. Somebody please help!!! Thanks
Click to expand...


With you having to pump the gas like that it almost sounds like it might be your accelerator pump...have you checked into that?
 
well...

I haven't done that trying to get the throttle up, but I was going to pull the carbs this fall:

Check fuel pump valves operation as follows:


Connect a clean plastic tubing to the fuel inlet nipple (see Picture A) and alternately apply pressure and vacuum with the mouth. The fuel inlet valve should release with pressure and hold under vacuum.
CAUTION: Some fuel may be present in fuel pump. Be careful not to swallow fuel when testing.

http://www.seadoosource.com/mikunitests.html
 
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