'97 GTX not revving up properly

[bjg214]

I have a 1997 seadoo GTX which was fully restored last year. So far, I've put about 12 to 15 hours on it since the rebuild and everything has been working great. Yesterday however, I noticed the ski was starting to not reach max rpms or speed. Instead, it felt like it didn't have enough torque to plane out and would only reach about 20 to maybe 25 mph. However, if I hit a wave that got the impeller out of the water, it would rev up like its supposed to for a few seconds then go right back down. Is this a water regulator issue or voltage regulator issue or something else? The lake is kinda far from my house so testing things are challenging. Any help would be greatly appreciated.

 

[mikidymac]

Sounds like you might be starving for fuel but for such a dramatic drop in performance I would check compression before doing anything else.

 

[etemplet]

Having the same issues with one of my GTXs. I have tried many things and spent lots of hours with the carbs. Basically both the GTXs are running rich and both performed much better when the weather was cooler.. I've tried every carb setting, looked at the Rave valves today, the water regulator, spark plugs, fuel pump, fuel system, etc... near as I can figure it is so hot the air density is affecting the skis performance. The ski we are having the biggest problem with sits at 35mph no matter what you do to the throttle. Back off, hit it hard, sneak up on it, then.... all of a sudden the ski takes off, sometimes after hitting a wave like you mention. LOL I opened the high speed screw on the PTO to the prescribed setting... the ski only went 28mph. Yep... it's rich but when it hooks up.... it rocks to 7K RPM. The other ski (a 1996 GTX) lost 300RPM up high but that may be exacerbated by a water regulator leak. I will find out tomorrow. I opened up the high speed screw to the recommended setting on that ski and lost another 150RPM off the top end (down to 6340 on top end). The skis are dying in the corners if I let the RPMs drop off and won't accelerate until I get them pointed straight and acceleration is sluggish. I don't feel like this effect should be so pronounced but... obviously it is. I am seriously considering dropping down from 142.5 mains to 140's. There is no carb setting that will completely correct the situation. I'm not done testing yet but soon I will be. No cheap kits in the carbs and I just installed genuine mikuni needles and seats which brought the pop off setting about 8psi higher. I'm gonna get to the bottom of this and when I do..... yeeeeehaaaaaa !!! Good Luck !!

 

[tingraham]

Take a minute to look at my post. I'd be interested if yours sounds the same to one of the videos I posted.

96 XP cutting in and out at 3/4 - full throttle

 

[etemplet]

Take a minute to look at my post. I'd be interested if yours sounds the same to one of the videos I posted.

My ski won't show any issues out of the water. I surely agree with Matt on checking the ignition/spark plug wires. I recently had an issue with exactly the problem he mentions. I don't think my problem is electrical. If it were it would not run worse or better when I messed with the carbs. For my ski, the difference in performance is unbelievable. You gotta hang on !! It will stay at top performance till you let the revs down below 5k. Once I point it in a straight line, it just takes a bit then it hooks up again. This situation improved dramatically when I ordered genuine Mikuni needles and seats also I set the pop-off to 32psi. One think I noticed about the pop-off setting. When you raise the pop-off, the sooner the needle reseats and holds pressure. My ski was set at 23psi, then 27psi, then 32psi with mikuni needles and seats. It always hooks up now but it is sluggish to do so. I have the PTO high speed adjuster closed on both my skis. What I've experienced is that no matter what I do... the ski is rich. I am convinced it is the carbs. I will check my prop as I have reason to do so. I have also ordered 140mm jets because I want to test that set up. I am gonna find the problem.

For now, both skis accelerate smoothly but don't LAUNCH when you nail the throttle. Perhaps this is how the GTX performs. I"m not gonna call it bogging.... more of a flat spot. Soon as the prop gets some air or is able to break loose, the response is immediate.... WARP DRIVE. I'd call it peaky in dirt bike language. The ski is very rideable as is but if I want to cut up and throw it around... I gotta keep the revs up.