2002 gtx di missing

[jimmyluke]

First of all I want to say thank you to the forum for all the useful information!
I took my 2002 GTX DI out today for the first time since I owned it- it ran good for first 10 minutes that I was on it by myself. Although I was a little disappointed that it only reached 40 mph. I came back to the dock to pick up my wife and as we headed out in the no wake zone I thought I noticed a little bit of a miss. when we got out of the no- wake zone I accelerated slowly as to test it so from idling at 1450 rpm's all the way up to 4000 RPMs it cuts out and or Misses but when it hits 4000 RPMs it kind of clears up and goes away and Then can only go up to about 6000 RPMs . BACKGROUND:
I recently purchased the ski without test riding it . The ski has 57 hours on it and the motor has 40 hours on it- the previous owner put a new SBT engine in it because engine was seized when he purchased it. Compression is 130 on both cylinders when dead cold. I read on the forum that DI's are critical with the fuel pressure and the oem fuel pumps are not reliable so as a precaution I replaced it with a "hi flow" model HFP342 DI as doo-wacka recommended in his how to blog. I did not replace the in-line filter but it is on order though. I don't know my fuel pressure however I did order a fuel pressure testing kit which I know I will have to modify to work on the Sea-Doo. Also when I changed the fuel pump I drained out all the fuel ,wiped out the tank and replaced it with 93 octane. The previous owner was running 89 octane but also in the forum I read that lower octane can cause engine damage even though the manual says they can run on 87 octane minimum. So the question is why is it cutting out between 1500 RPMs and 4000 RPMs and shouldn't it go faster than 40 mph? Sorry so long but I figured the background info might be helpful. Thanks for any help you can give me!
JIM

 

[gortex]

Mine did almost the same thing when I had it out last year . I think it was the grey tempo fuel lines they break down due to the ethanol in the gas. Mine had almost plugged the fuel selector valve. I just finished replacing the fuel lines, selector valve and rebuilding the carburetor. I haven't had it out yet to test but I think that is what the problem was.

 

[jimmyluke]

Thank you for your comment. However my ski does not have the gray Tempo fuel lines on it and I don't think it ever did because of it being a direct injection machine. Hope you got yours straightened out.
JIM

 

[jimmyluke]

Also the DI's don't have a fuel selector valve or carburetors. Good luck

 

[Coastiejoe]

You are in the right path with obtaining FP pressure and what not. It is likely good, but it is best to know.

The DI ski is a beast all its own, as I'm sure you've read.

Voltage is also critical with the DI application. There is a chance that your rectifier is producing some A/C voltage, if so, it affects how the ski runs in the higher RPM range. Simply unplug it and see if the problem goes away. You can also test for A/C voltage at the battery when it is running. If there is, the rectifier needs replaced.

 

[jimmyluke]

Thank you Coastie I will try the ac voltage check when I get home from work tomorrow thank you. By the way my in-line fuel filter just came today and as I suspected there were no fuel lines. Do you or anyone else know where I can get the appropriate fuel lines and or the part number of the fuel lines (hoses) that would meet the criteria of my DI machine.

 

[mikidymac]

First to say I am no DI expert.
Are you trying to add a secondary inline fuel filter?

 

[jimmyluke]

No I do not want to add an additional fuel filter, I am just replacing the one that I do have. The new filter was advertised as comes with all the hardware necessary and instructions. however the filter only came with two pex type clamps ( no hose) and instructions were to cut off the factory hydraulic type crimps on the inlet and outlet hoses of the filter. This will make my hose too short. So I'll need to purchase some hose- no problem but I just want to make sure it will take the pressure and any other oem requirement . Thank you. JIM

 

[jimmyluke]

I tested the battery while ski was idling and there was no AC voltage present at the battery

 

[jhjesse]

Need to have the meter on VDC. Rectifier coverts AC to DC

 

[jimmyluke]

Thank you for your comment. I was testing how Coastie Joe told me to and that was to check for AC voltage at the battery while the engine is idling and if there is AC voltage that meant that the rectifier was bad. Thanks.

 

[tkarvelis]

If you are referring to the grey filter on top of the pump, you can cut the clamps off the old filter and install the new one. Make sure the clamps are rated for Fuel Injection, and not the cheaper clamps.

Measure the DC voltage. It should be around 13 at idle and around 13.5 at 3000.

Have you changed your plugs? If not, do it. The skis like fresh plugs.

What are your compression numbers, and what are your RPMs at 40 MPH? You could have a bad wear ring causing the low speed.

 

[jimmyluke]

Thank you for your reply. My compression is 130 on both cylinders and yes I put brand-new plugs in it before it's maiden voyage. My maximum RPM was somewhere around 6500 at 40 mph. After about 10 minutes of running it started acting up and then I couldn't quite hit 6000 RPM at maybe 38 mph .A quick visual on the wear-ring looks like it's fairly tight clearance on the sides but the top and bottom show more wear- maybe in the .030" ball park. I did not get a chance to actually measure it yet. I guess the best way would be to remove the reverse gate and nozzle and check it from the back? i'll get back to you on the voltage- my meter was getting some weird readings and I found out that my battery on the meter was low. Actually I was getting some inconsistent readings- about 14.5-15.5 volts with the engine off (with the meter with a low battery) . I will get some readings tomorrow with engine off and with engine running. Did I see that you had a 2002 GTX DI? If you do what maximum speed and at what rpm do you run? What rpm are you running at 40 mph? I'll probably just go ahead and order a new wear-ring if I don't need it now I'm sure I'll need it sooner or later. That being said are aftermarket wear-rings ok or stick with OEM or some other namebrand? More on the fuel filter later. Thanks again. JIM

 

[jhjesse]

At 14.5 to 15.5vdc your rectifier is bad. Too much voltage is just as bad as not enough voltage. Rectifier is allowing AC current into the system. AC current make these skis act very strange sometimes. I would replace with OEM rectifier.

 

[jimmyluke]

I'm sorry I should've clarified- now with the new battery in my meter And the engine off I get 12.91 Volts on 1 meter and 12.83 Volts on a different meter. I will check running volts tomorrow thank you. JIM

 

[mikidymac]

If you are turning 6000 rpm and only getting 40mph then either your wear ring is bad, impeller is bad, your carbon seal is bad or a combination of all.

 

[jimmyluke]

Thanks mikidymac- I ordered a new wearing and pump seal today. Thanks again.
I did check my fuel pressure when the ski was running the pressure was 104 psi. As you know the book says 107 psi + or minus 2 psi. Hopefully that is sufficient? I did check my voltage while the machine was idling it was 13.6 V and at 3000 RPM it was 13.6 V. Also it did not have any AC voltage like Coastie Joe said to check for meaning that the rectifier was OK. Just wondering if after The ski warms up if that could change? I'll have to take it out for a ride and try that next I suppose. Because like I mentioned earlier in this thread the ski ran good other than only going 40 mph but it didn't start missing in the 1500 to 4000 RPM range until about 10 minutes of running time. Thanks for your help. JIM

 

[jimmyluke]

Good news (I thought). Even though my old rectifier tested good as mentioned above, I hooked up my new rectifier without mounting it and did a quick test at idle it was 13.1 V. I took it for a ride and rode it for about an hour or so and no problem- so it was not cutting out at all even up through 6500 rpm's (still only hitting about 40 mph but I have a wear ring coming any day now and hopefully that takes care of the top end). I was very happy! When I got home I decided to test the voltage just out of curiosity and at idle it was 13.6 but shortly after It started climbing up to 15.2 V at idle and then 17.2 volts at 3000rpm! I checked it with 2 meters and read virtually the same. (Crap). The battery is supposedly only one-year-old. Any ideas? I would assume it's not good to run it this way?

 

[tkarvelis]

Regulator is bad... Is it oem? Or ebay?

 

[jimmyluke]

It is an ebay rectifier. I really wish I could order parts from Sea-Doo warehouse.com by using my iPhone over the Internet or by phone call. I don't see a phone number listed. I think one of the guys on the forum here is associated with them? I would be happy to send them some business.
Thank you Tkarvelis
JIM

 

[tkarvelis]

If not go to OSD.com. Nick will take care of you. The 4tec rectifier he has will plug into the di. It is heavy duty. You will need to modify the bracket a bit, but it will last forever.

The other option is oem

 

[jimmyluke]

Ok thanks for the recommendation.

 

[jimmyluke]

Well I put in my new rectifier from OSD parts.com hoping to fix my voltage problem. Also I put in a new wearing hoping to get more than 40 mph from top end. I was a little disappointed with my clearances: they were .014" at 12 o'clock position, .014" at 3 o'clock position, .022" at 6 o'clock position, and .012" at the 9 o'clock position. I thought my clearances would be tighter than this and obviously my jet pump housing is egg shaped some. The shaft is not bent because all the individual blades on the impeller indicate the same clearance in any one spot. When I had the jet pump off I noticed that two of the four plastic bosses that have the threaded metal insert in them that fastens the Venturi to the jet pump were cracked. Upon assembly of the pump these two cracked bosses did not torque to spec - they acted as if it started to strip the threads but I'm guessing it's just continued to crack the housing further so I stopped and I figured I would try the ski out anyway hoping it would hold together.
Moving on: I backed the ski into the water left it on the trailer started it up- it idled OK, but when I revved it up it kind of bogged and then revved up some and then died. It did this several times in a row. I pulled the ski out of the water put two new plugs in it put it back in the water on the trailer and it did the same thing. I had it running no longer than 30 seconds but one thing I did notice was no water coming from the pee-hole. I got disgusted and went home. So after getting home ( about three hours after the engine ran last) I checked the compression and I had 135 PSI in both cylinders. (I had 130 psi the last time I checked it with about two hours of running time since then) I checked the voltage at the battery-it was 13.5 V at around 3500 RPM. I checked the fuel pressure it was 95 psi at idle and when it revved up it held at 100 psi. The engine RPM and the fuel pressure seemed directly related to each other, The engine was kind of boggy at 95 PSI but when it finally revved up- at the same time the fuel pressure came up to 100 psi. The last time I checked the fuel pressure (Less than two hours running time ago) I had a steady 104 psi at idle and revved. I know I'm looking for 107 psi. I do have a new in-line fuel filter for it I think I'm going to put it on. Sound reasonable? Any suggestions? Also how soon should I get water coming out the Pee-hole after I start it in the water? Also one added note I did not put any sealant between the Venturi and the jet pump-it did not call for it in the manual but I was debating whether I should or not. And also between the jet pump and the hull I did not put any sealant- i used a brand-new rubber seal.
I hope you all had a enjoyable Fourth of July. Thank you for any help Jim.

 

[mikidymac]

Your fuel pressure is too low and a DI won't run without perfect fuel pressure.

 

[jimmyluke]

Hopefully the new fuel filter will fix the problem. If not I'm going to pull out the new pump with less than two hours on it and put in the original. I never did test the original OEM pump. Between the time that I bought the ski and taking it for my first ride I read on the Sea-Doo Forum that the OEM fuel pumps were not reliable and that the fuel pressure was critical. I also now have a way to test my fuel pressure.
Thanks again Jim.