2002 GTX DI Throttle Sweet Spot

[HateMyGTXDI]

Hello,
I'm new this forum and see many helpful people. Hopefully someone can help. I've searched the forums but don't see my exact issue. I have a 2002 GTX DI that is in some sort of limp mode until I get the throttle in just the right position, then it will take off, but only up to 35 MPH. I know this Seadoo should do at least 55 MHP and more, but mine won't.

Here's the situation:

I bought it used about 8 years. It ran pretty good when I first got it, but then it sat for a while. After taking it out again last season, and this season as well, it definitely goes into limp mode. Upon starting it, it beeps twice (which I think is right) and then one long beep. It's flashing "low oil" so I'm assuming that's what the long beep is. I have addressed the low oil. No other Maint Lights or beeps. It will start fine, both on the trailer and in the water. It will usually idle fine in the water but when I push the throttle, I won't go over 4000 RPM's and not over 10 MPH. However, when I get the throttle in just the right spot (Sweet Spot) it will take off. It will get to 5500 RPM but only about 35 MPH and run OK for a while, but if I go past this sweet spot or before that sweet spot, it will again bog down to 10 MPH.

I have:
Checked voltage at the battery:
12.0 volts before start
12.8 volts while running (seems low to me)
Charged the battery
Changed Spark Plugs
Pulled the injector assembly and watched them spray. It seems like a good spray and both seem even. I plan to pull them and clean them
Replaced the air solenoid valve
Replaced one-way check valve
Checked compression: 115 at both cylinders - Is this low?
Checked fuses all good - I read there is a 1 amp fuse somewhere but can't find it
Checked wiring harnesses and all seem tight

I have not put a Candoo Pro on it yet to see if there are any codes.
I have not replaced the TPS's yet but suspect this could be one of the issues.
I have not pulled the RAVE valves yet, but plan to. I had trouble finding the right gaskets.

Someone replaced the fuel pump recently as a "favor", but I'm sure it wasn't an OEM fuel pump. Not much of a favor. This may be causing the problem because of the amp draw, and the fuel filters were replaced by same person.

I know many have experienced the limp mode issue, but has anyone experienced this issue where the sweet spot allows it to run? Any suggestions would be great!

Thanks!

 

[j.harris]

135psi is perfect on compression for the 951, I don't know if 115 is too low. I don't know much about these DI skis but it seems like fuel pumps are a major problem and aftermarket ones rarely work well. I wish I could help more.

 

[jhjesse]

Low compression.
Aftermarket fuel pump drawing too much amperage. Rectifier voltage is low most probably because of fuel pump drawing too much amperage.

 

[POPPS]

I have yet to be blessed with an after market pump that works in "the water!"

 

[HateMyGTXDI]

My apologies for taking so long to reply to this. I purchased a used Candoo Pro and have been waiting for it to arrive. I connected it to my GTX DI and found several codes. I wasn't able to export the codes for some reason so I took pictures of the results on the Codes Tab. Can someone here help me evaluate the results?

 

[POPPS]

Your 12.0 intial battery voltage is/was low, should be around 12.7 V, and the charging voltage should be 13 plus.

 

[POPPS]

I have had skis that will start, but will not give you the initial 2 beeps if the initial voltage is 12.6'ish volts. You already know that it is not charging enough, DI's are very sensitive to voltage fluctuations,,,that may affect the readings that the MPEM receives from all the sensors on the DI...there are too many of them!

 

[HateMyGTXDI]

Thank you all for the responses. So replacing/charging the battery could/may/will resolve these issues? I will replace the battery and test if it does.

 

[POPPS]

Before you get a new battery, check to see that your charging circuit is working, I would ckeck every connection on the ski, then test to see if the stator is sendind out its appropriate voltage, if yes, then your regulator will more than likely be the culprit, which occurs frequently on DI's.

 

[HateMyGTXDI]

thank you! I will check/clean the connector and figure out how to verify that the stator is operating correctly. I did use a volt meter to check the charging amps while running and only showed 12.8 volts, so could be the regulator.

 

[jhjesse]

All those codes are inactive or occurred. You can clear them and see if they come back. There doesn’t appear to be any active codes.
As I said in post #3 drawing too much amperage can cause the electronics to go crazy and throw all different sort of codes. Also a bad rectifier will cause electronics to go crazy by allowing too much AC voltage into a DC system.
Rectifiers not putting out enough voltage can also cause electronics to act goofy.

 

[XPLORx4]

I have an 02 GTX DI, and it's had low voltage problems which have resulted in limp mode several times. In combination with MAINT flashing, the display has also shown 12V LOW. The battery has been load-tested as good. The issue has been intermittent, however, and it seems that if I keep the battery fully charged on a Battery Tender until the day I take the ski out, all is well. I decided to install a voltmeter inside the glove box to monitor the voltage while riding, and the last time I took it out with a fully charged battery, the voltage was fine. I think the magneto/rectifier output is just barely enough to keep the electrical stuff (fuel pump, etc) running if the battery is strong. If the battery is weak, I think the system can't keep the battery voltage where it needs to be (or charge it sufficiently) while powering the fuel pump and ignition.

 

[mikidymac]

An aftermarket fuel pump will usually cause too much current draw and cause electrical issues also.

 

[HateMyGTXDI]

I didn't have a lot of time but I finally got a chance to get back into the GTX DI. The battery was low so I charged it but haven't replaced it yet. It's a 5 year old AGM battery. But I found a broken stud on the exhaust manifold and the RAVE valves look pretty bad. I haven't removed them yet but when I do remove them, I might as well clean them and replace the bellows, gaskets and O-Rings. Can anyone tell me what the best RAVE valve rebuild kit would be for this '02 GTX DI and where to get it? I need to find the right stud also. I'm assuming performance will suffer if the exhaust manifold is leaking. Also, should I be able to move the RAVE valve with my hand by removing the cap? I haven't had a chance to check/clean the connectors yet. Getting ready to do that now.

 

[POPPS]

If you use a pair needle nose pliers for better grip, you should be able to move the valve up and down, but there is slight resistance due to 2 underlying "O" rings. I would disassemble each entire valve and start from scratch. You may not need a kit depending on the condition of the "O" rings.

 

[HateMyGTXDI]

I want to say thank you all for the responses. Although I haven't tackled the fuel pump or fuel pressure issue yet, I wanted to address the broken head pipe/exhaust manifold bolt as I know this could cause engine issues and assuming could suck water back into the cylinders.

I removed the head pipe/exhaust pipe from the exhaust manifold and found that the exhaust port looks to be damaged. I'm posting a picture for your review. It is hard to see, but the "ring" of material that forms the exhaust gasket channel seems to be missing a piece. I don't know if the piece fell into one of the cylinders but I can't find it. I know others before me have messed with the exhaust manifold because of the broken bolts. The two other Allen type bolts were not very tight either and the 4th stud appears broken too. I think the stud has a nut instead of an Allen type bolt, but the bolt was not on the stud, so only two of the bolts where holding the exhaust manifold on. The exhaust gasket looked like it had not been replaced, either. Do you think this exhaust manifold is no longer usable?

Also, I saw a post on using ATF and acetone to break loose broken bolts and am trying that now on the broken bolt and the broken stud.

And is the exhaust gasket still available? If I need to replace the exhaust manifold, where is the best source to get one?

thanks again!!!

 

[mikidymac]

Yes, the o-ring gasket is still available.
You are going to have to use a penetrating lube and lots of heat on the aluminum to get that stud out.

 

[HateMyGTXDI]

Thanks mikidymac! Looking at the pics, do you think the manifold is damaged beyond use?

 

[mikidymac]

Looks fine to me, just give it a good clean with a wire brush and a little 1211 on the gasket/o-ring. Also make sure you have the "diaper" to go back over the joint.

 

[etemplet]

Man... your username is very negative. Mechanical devices pick up on that and hate you right back.

 

[HateMyGTXDI]

Man... your username is very negative. Mechanical devices pick up on that and hate you right back.

I'm beginning to believe you etemplet. I will see about changing my username. Maybe MyGTXDIHatesMe? I have definitely offended it.

 

[Wess]

Like others said, your voltage is to low. I just put my ski back in the water and had similar problems. My rectifier was one of the problems. I replaced it with a SPARK oem rectifier and it puts out 13.8. I put an aftermarket pump in and it runs great. See my post in here and it will give you an idea of what I went through.

 

[Tyman2020]

Like others said, your voltage is to low. I just put my ski back in the water and had similar problems. My rectifier was one of the problems. I replaced it with a SPARK oem rectifier and it puts out 13.8. I put an aftermarket pump in and it runs great. See my post in here and it will give you an idea of what I went through.

You make sure you say your tanks to the god you believe in because getting a aftermarket pump to function in my di is impossible lol.

 

[Wess]

You make sure you say your tanks to the god you believe in because getting a aftermarket pump to function in my di is impossible lol.

I guess you had to buy an OEM one. No problems with mine, proper pressures, starts right up, no hesitations and maintains around 52 top end.

 

[etemplet]

Is that the Large Hull GTX?? I have a 2003 951 DI. I was wondering about the top speed.