I've had this 98 GSX Limited for several years now. Everything has been good on the ski. I winterized the ski last fall, just like every year and am having an issue this spring. At WOT the ski runs strong at 6700 RPM for about 10 seconds and then goes down to about 5500 RPM. If you keep on it after that, it will eventually die. If you let off the throttle before 10 seconds, then everything is normal. It runs perfect at low and mid RPMS. After the first time out, I rebuilt the carbs and checked the RAVE valves (Carb settings were put at factory). The carbs were pretty clean, the filters were a little bit dirty. I checked the water regulator and it seemed to be fine. It has good compression also. I've got new spark plugs in it and nothing seems to be fixing the issue. Has anyone come across anything like this? I can't think of what to try next. Thanks!
98 GSX Limited Losing RPM at WOT after 10 seconds
- Thread starter jdparr15
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- 1998 gsx limited gsxl seadoo
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SabrToothSqrl
Well-Known Member
The 1998 GSX 951 Carb limited doesn't have a separate rectifier.
This issue sounds fuel delivery related, does it have the original grey "tempo" labeled fuel lines?
If so, ethanol fuels (thank the goobermint) will dissolve them from the inside and they will clog with a greenish goo and run your engine lean.
You need to get some new lines. The thicker line is 5/16" and the smaller is 1/4" you'll need about 12-15' of 5/16 and 5' of 1/4"
There is also a fuel filter under the front storage bin. Remove that white bin and you'll find a small white fuel filter. Clean that out, or ideally buy a new one.
While we are at it, the 951 carb needs a very specific oil. Anything else will quickly destroy that engine. Run the OEM XPS-II or it's specific equivalent. (I only use the XPS-II).
If it's not fuel related, it may be spark related. The 98 didn't have the TPS of the 99+, so it shouldn't be that.
have you tried clipping the plug wires back 1/4"?
And yes, if you suspect a charging system issue, check the battery voltage, at the battery. engine off should read 12v, engine on should read around 14 at idle out of water. (3,000 RPM). Don't run the engine more than 20-30 seconds, but you can run that long without water.
This issue sounds fuel delivery related, does it have the original grey "tempo" labeled fuel lines?
If so, ethanol fuels (thank the goobermint) will dissolve them from the inside and they will clog with a greenish goo and run your engine lean.
You need to get some new lines. The thicker line is 5/16" and the smaller is 1/4" you'll need about 12-15' of 5/16 and 5' of 1/4"
There is also a fuel filter under the front storage bin. Remove that white bin and you'll find a small white fuel filter. Clean that out, or ideally buy a new one.
While we are at it, the 951 carb needs a very specific oil. Anything else will quickly destroy that engine. Run the OEM XPS-II or it's specific equivalent. (I only use the XPS-II).
If it's not fuel related, it may be spark related. The 98 didn't have the TPS of the 99+, so it shouldn't be that.
have you tried clipping the plug wires back 1/4"?
And yes, if you suspect a charging system issue, check the battery voltage, at the battery. engine off should read 12v, engine on should read around 14 at idle out of water. (3,000 RPM). Don't run the engine more than 20-30 seconds, but you can run that long without water.
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Prime Target
New Member
Dirty fuel selector switch.
Prime Target
New Member
I'd just replace it. It's around ~$20 for a new one. I had a similar problem last year after I replaced my fuel lines and rebuilt my carbs. I just cleaned the selector switch and reused it. Thought I cleaned it well but ran into fuel starving issue first time out. I was told the switch was probably still dirty and to replace it. I installed a new one which fixed the problem completely.
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