97 gtx wont rev past 4700 rpm. HELP!?

Note: This site contains eBay affiliate links for which SeaDooForum.com may be compensated
Status
Not open for further replies.

Geeledouche

New Member
Newbie here.

I recently purchased a set of 97 sleds. a GTX and a GSX. I really like the gtx because of its size but I finally took it out for a spin yesterday and once I got out of the wakeless zone I gunned it and it didn't hardly move. the throttle stumbled a lot and I had to kind of milk the throttle just to keep it running. After about 10-15 minutes of trying everything I can think of to get it to rev higher, if I SLOWLY increased throttle it would finally get up to 4500-4700 rpms and stay there as long as I held the throttle in, but as soon as I let off it would bogg out and try to die.. I know its idle is low. In the water its only around 780 rpms at idle and it kept dying. Ive done a lot of googling (frankly it was a little disheartening for my first time on a jetski) and it gives me some ideas like to clean the rave valves. Ive never done that before but the videos make it look pretty easy. I'm guessing a carb problem could also cause this type of problem too couldn't it? any other suggestions on what to look for or what I can do to get her going?

Also, I forgot to mention,, once I got the machines home I started the gtx up and it revs up just fine out of the water. Maxed out around 6700 rpms or so. no hesitation or sputtering. It would hit the 6700 ish max then back itself off a little.

Thanks for the help guys!

ps- the gsx also had problems on its first ride. the VTS was stuck in the top position and wouldn't move. After a brief google search I found that the motors go bad frequently. I popped the cover and it was corroded badly, so I ordered a new motor I'm fairly certain that will fix the issue with the VTX. other than that it ran very well.
 
Last edited:
Most likely its your carbs. Do they still have the grey fuel lines? If so change them out. When you rebuild the carbs, get genuine Mikuni kits, not an aftermarket kit. There is a difference. There is a carb rebuild sticky, follow it and you should be golden. Also go ahead and download the manuals for both machines. They are invaluable.
 
I'm not sure I have the finesse to rebuild the carb on my own. It looks a little difficult. does anyone do this as a service by chance?

Also, if it was the carb, wouldn't it perform the same in and out of the water?
 
The carbs and fuel system are the first thing that need attention. If you still have grey fuel lines, they need to be replaced with regular black automotive lines. You should also replace the fuel selector switch and the O-Ring in the filter/water separator. Next you will want to rebuild the carburetors with genuine Mikuni parts kits. I generally buy mine from OSD Parts, as I know they are OEM and the offer complete kits with new needles and seats.

The carbs are really very simple, so there is no reason to be intimidated at all. Just disassemble then one at a time so that you have the other to reference if you need help figuring out what goes where. Follow Mikidymac’s carb rebuild sticky on this forum and you’ll be fine. There’s really no reason to send the carbs out. I will recommend that you go ahead and order two sets of the internal carb screws when you get the parts kits though. They have a tendency to strip, and the worst thing a beginner can do when rebuilding their first set of carbs is to disassemble them and then have to wait a few days for parts before putting them back together. After the first time, you’ll remember where everything goes, but trying to remember how it assembles after waiting a week is tough.
 
Just to add to the above....
1. Running on the trailer will tell you absolutely nothing other than it runs.
2. You can take a look at my carb rebuild thread and see if it's something you want to try. IF not send them to PWC Muscle for rebuild.
3. You still have to replace the gray fuel hoses, ON/OFF valve and strainer and/or o-ring.
4. Stop running them as you will damage the engines until you service the fuel system.
5. If the VTS is corroded it's probably a bad brain and motor. You are better off getting a complete tested unit from Westside Powersports, Nick and Jess. A bad VTS can fry the computer so unplug all the wires going t the unit until it is fixed.
 
Thank you all for the replies! I will order a couple kits and give it hell. Looks like they are about 50 bucks per kit on amazon right from mikuni. I'll have to take a closer look and see what fuel lines are currently on it. If they have already been replaced with the black ones, do I still need to replace them? Also, what is this strainer and o ring that needs replacing? I can figure out the on/off valve. do I just replace that with a T valve? or even bother with turning it off at all? or just plumb it always on directly from the tank? thanks guys !
 
If it were me I would get the "Back to Stock" kits from OSD Seadoo Parts with needle and seats that will include everything you need for the carbs and base gaskets. I would add a new ON/OFF valve from them and if you don't want to replace the entire strainer at least order the o-ring, again from OSD.
 
The strainer/filter is the white plastic “cup” that sits right above the fuel tank and under the steering. This is a common place for air leaks if the oring is old and brittle. It also acts as a water separator, so it should be removed and emptied on occasion so that it doesn’t fill with water over time.
 
I got this far in my disassembly last night. Questions in the next post..
 

Attachments

  • 52B1261D-9D47-4D5B-BB94-F6AF134CD79F.jpeg
    52B1261D-9D47-4D5B-BB94-F6AF134CD79F.jpeg
    1.4 MB · Views: 20
Last edited:
So, I did a little work to my machine last night. I tried to get the carbs off. I'm to a point that I don't know what bolts come out next. How are these mounted to the engine / intake? is it the 2 bolts in the middle of the carb that go straight through or do I take the entire intake manifold off? Also, while messing around I noticed that all of my fuel lines have been replaced with the black fuel lines and does NOT have anything between the fuel tank and the carb (no strainer/separator), but I saw something that was a little concerning,, (picture below) on the top of the oil reservoir I noticed it had a line going to the motor and what appears to be another barb that doesn't have a line attached to it. Is it supposed to have a line on it? or should I cap it? Thanks for all the help guys! Sorry for all the newb questions.
 

Attachments

  • 2BFDCE71-3C96-4208-BE4A-E0927B764255.jpeg
    2BFDCE71-3C96-4208-BE4A-E0927B764255.jpeg
    1,012.4 KB · Views: 16
That " barb" is your check valve for the oil tank.

There should be 4 hoses coming off the top of the fuel sender.
1- VENT out the side of the GTX with a check valve
2- ON to the selector - then to the water separator and off to the carbs
3- RESERVE to the selector - then to the water separator and off to the carbs
4- RETURN from the carbs.

Have you downloaded a manual for your machine? These are invaluable and show not only what bolts need to come out but also what sequence and torque specs they need for installation.
 
I have downloaded it but I'm not able to save it for some reason. I'll have to try again.
I'm decent at reading schematics and blueprints so I get a lot of information off the parts fiche.
Thanks for the help guys!
 
The only bolts holding the carbs on at this point are the four larger Allen head bolts running through the carb bodies. Go ahead and pull the fuel inlet and return lines while everything is still bolted down though.
 
It also looks like the pulse line from the fuel pump cover to the engine block is not the molded oem one. If it is kinked, pinched or too soft it can cause the fuel pump to not work correctly.
 
Thanks guys! I will finish taking them off and get them attended to asap. I sure appreciate all the help.

I did notice a very heavy gas smell under the seat when disassembling the intake. I'm assuming my carb is leaking fuel and that is why I'm not getting full power. I'm just damn lucky I didn't start a fire!
 
Check to see whether the vent line that is connected to the thru hull fitting under the hood is working. You should be able to blow air in, but not suck air out. If that check valve is bad and disconnected, it will let vapor into the hull.
 
Status
Not open for further replies.
Back
Top