1998 GTX Limited surging?

[Edwinh12]

I got a 1998 GTX Ltd that is doing exactly what is happening in the video link I provided at the bottom. It’s okay off the jump and then once I get closer to half throttle, it starts doing that. I have rebuilt both carbs with mikuni kits, rebuilt the rave valves, all new fuel lines, new fuel filter, new fuel selector and siphoned out the old gas. I have also checked the rectifier and its within manuals spec. I played with the low settings out on the water and just couldn’t get it fixed. Could my high screws be in to far or what else would cause this? 130 130 compression (which is perfect I believe for a 951) starting up instantly and idles perfect.

Link - (not my ski, just found one on YouTube doing the same thing) -

 

[Grim]

Hey, I got the same ski and I answered you on Facebook, somewhat, if you do a quick search on this forum there is a guide on how to adjust your high speed adjuster. I would set it to factory first, check it out and if it is doing the low power drag. I would do a spark plug check by doing a throttle chop and seeing what your spark plugs look like. That can tell you if you are lean or rich. Also, what fuel line did you use, could it be collapsing? Another idea is to check your coil. I would also verify you have no air leaks with that new fuel selector, they are notorious for leaking air right out the box. Lastly, get new spark plugs and verify they are an exact match for your ski, NGK BR8ES

One word of advise, if it has seals or is electrical try to go OEM as much as possible. Aftermarket parts are not reliable, IMO. Also, you can download the maintenance manual and the parts manual free online, it will help you!

 

[Edwinh12]

I used a high quality fuel line, not sure of the brand off the top of my head so I’m positive that’s ok. I somehow haven’t changed the spark plugs so that’s something I need to just cross off my list. A few questions, how would I verify my fuel selector has no air leaks? And what do you mean by checking the coil? I’ll do some research on my end but I’m not sure where the coil is. Thanks for the help.

 

[Grim]

One way to check the fuel selector is bypass it, take the main gas line going to the carbs and run it to the line going to the gas tank hose, I know there are a few lines but I'm sure you can figure which is which. Does it bog when you throttle up out of the water as well? If you don't know , test it real quick and see. You can run the motor for a little bit with no water, it wont hurt it, just not more than 20 or 30 secs at a time. it only takes like 5 to 10 secs to do that . One other thing I would check is the spark plugs wire themselves and the boots. Make sure the wire is seated inside the boot at the spark plug.
the ignition coil is what produces the energy for the spark plugs to go off. It is located in the back , in a small black box. It is a little bigger than a first, normally black. Yu can trace the spark plug wires directly to it. If it is on its way out it could be getting weak, but that is a long shot. You can test it by getting a spark plug inline tester and rev the motor to see if the spark weakens. There is a multimeter check you can do, but I don't recall acceptable range for our coil. Ill look for it, I tested my coil a few years ago when I was rebuilding everything.

 

[Edwinh12]

One way to check the fuel selector is bypass it, take the main gas line going to the carbs and run it to the line going to the gas tank hose, I know there are a few lines but I'm sure you can figure which is which. Does it bog when you throttle up out of the water as well? If you don't know , test it real quick and see. You can run the motor for a little bit with no water, it wont hurt it, just not more than 20 or 30 secs at a time. it only takes like 5 to 10 secs to do that . One other thing I would check is the spark plugs wire themselves and the boots. Make sure the wire is seated inside the boot at the spark plug.
the ignition coil is what produces the energy for the spark plugs to go off. It is located in the back , in a small black box. It is a little bigger than a first, normally black. Yu can trace the spark plug wires directly to it. If it is on its way out it could be getting weak, but that is a long shot. You can test it by getting a spark plug inline tester and rev the motor to see if the spark weakens. There is a multimeter check you can do, but I don't recall acceptable range for our coil. Ill look for it, I tested my coil a few years ago when I was rebuilding everything.

Ok I will add those onto my things to check. Yes the jet ski sounds perfect out of the water. Doesn’t hesitate at all but after reading, I never adjusted the accelerator pump when rebuilding the carbs so that’s something i need to check as well.