2002 GTX deteriorating performance

[BYOC]

I just purchased a 2002 GTX about a month ago. First couple times out, it could get up around 50mph. Now it’s only doing about 30.

The only thing I can think of is maybe I’m using the wrong fuel. Since it’s a 2-stroke I just assumed always use ethanol-free and the highest octane you can find, which for me has been 91. But I’ve read some people saying that 87 is actually the best for Sea Doos.

Maybe there’s something lodged in the impeller. I don’t see anything obvious, but I’m not sure how to check properly.

It’s also been giving me a low oil message when there’s plenty of oil in the tank. I’ll top it off and the message goes away, but comes back on after about an hour of use.

 

[mikidymac]

First thing, is your engine carbed or fuel injected?

The fuel won’t cause an issue. All Seadoo’s use 87 octane except the direct fuel injected 951 that requires 91.

The low oil light is just an idiot light with a float and won’t cause any running issues.

Finally what is your maximum rpm when wide open at top speed?

 

[XPLORx4]

I also have an '02 GTX. It's a DI. It's been a bit sluggish lately. WOT only gets to about 6580rpm @ about 47mph on relatively flat water. Last summer I was hitting 51mph at up to 6900rpm. I only run 91 octane. What should I check?

 

[BYOC]

It’s the GTX DI. Is that fuel injected? Max RPM is only 5700 @ 35mph. I haven’t been riding it lately. My kids were complaining about it not going as fast anymore. I took it out yesterday. It kinda sputters when taking off and getting up to top speed. And if I pull the throttle all the way, it only goes about 5400rpm/30mph and sputters a little bit. If I back off to about 3/4 full throttle, it runs smooth at 5700rpm.

 

[XPLORx4]

The first thing you should try is change the spark plugs. 2 stroke engines foul plugs more frequently than 4 strokers. I always carry spare plugs. The GTX even has a spark plug storage bin under the rear seat. Also check the battery voltage while running. DI engines don’t like low voltage and will enter limp mode if the battery is weak. This will also be accompanied by a long loud beep and the MAINT warning on the gauge.

 

[BYOC]

Replaced the spark plugs and she's running great now! Almost does 55mph on glass. Thanks!

 

[POPPS]

Way to go!