96 GTX losing high RPM’s

[Matuszak24]

96 GTX SeaDoo with all new fuel lines and clean rave valves, I can run great for about 15 minutes before my RPMs start bogging down around 6000 and then at 5500, will bounce down to 5000 and when I open the throttle as soon as it gets to 5500 will bog back down. Runnknf non-ethanol and and fully synthetic XPS. When I shut off the Sea-Doo and let it sit for about five minutes, it will run great for another teip around the lake before it bogs down again. Idles just fine at all times, everything under 5500 is fine. Any suggestions? If it were running too lean or too rich would it run as well as it does for 15 minutes? Has anybody had this issue that is found solutions for it?

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Could this be an issue with the high-speed or low speed screws that I have read about? If so, could someone maybe direct me towards where they are located? Are these screws different than the “jet” screw

 

[GGuillot]

96 GTX SeaDoo with all new fuel lines and clean rave valves

When you replaced the fuel lines did you rebuild/clean the carbs and install new genuine parts? New fuel selector? New Oring in fuel strainer?

Could also be related to a rectifier problem.

Couple things you could do to narrow things down, do a bypass in the fuel system around the selector and filter under the steering. For a brief run, you can disconnect the red wire on the rectifier when it starts having the bog issue on the top end. If no change I'd pull the carbs and have a look. On that ski LS needles (on bottom) at 1 turn out and the HS needles (on top) at 1/2 turn out should yield good results to about 6700. I have two 787 skis set this way.

Did you just get this ski? What's the history? most of the run issues on the carb 787 motor is carb related, sometimes a rectifier failure.

 

[Matuszak24]

Thank you for the reply! I’m pretty in-tune with automobiles but this is my first PWC. This one has been in my in-laws family since it was bought new. It’s got relatively low hours on it (130) and has always been maintained. I’ve been learning as I go in terms of how these things operate and most of the Do’s and Dont’s. Carb is one thing that I haven’t rebuilt yet, I guess my question regarding it would be....would the SeaDoo run perfectly fine from 0 to 35 mph and Idle no problem, start up no problem, if it were a carb issue?

Can you help me identify the rectifier? I read on another forum post about disconnecting that red wire but I wanted to make sure that I was locating it properly before I did anything.

Thank you!

 

[GGuillot]

Idle no problem, start up no problem, if it were a carb issue?

Yes, could still be a problem, try the rectifier and bypass first. Look in the front where the main MPEM (ECU) for the ski is located. In that box or area look for a square device with 3 yellow wires and a red wire. The 3 yellow wires are directly from the stator and convert AC current to DC current on the red wire.

When you disconnect the red wire don't do it for too long, your battery will then limit you and it could die once the voltage drops too much and leave you stranded.

You can download a free service manual to learn everything about your ski. SeaDoo Manuals - FREE PDF Download!

 

[Matuszak24]

Since this in an issue that usually occurs about 20 minutes into my first ride of the day, should I leave the rectifier the way it is, take it out on a test run, and then when I start experiencing the issue, then unplug the red wire and give it a run? Would that tell me if it’s the issue? I just don’t wanna run the thing for 25 minutes without the battery getting charged...

 

[GGuillot]

Since this in an issue that usually occurs about 20 minutes into my first ride of the day, should I leave the rectifier the way it is, take it out on a test run, and then when I start experiencing the issue, then unplug the red wire and give it a run? Would that tell me if it’s the issue? I just don’t wanna run the thing for 25 minutes without the battery getting charged...

When it occurs then you return to the dock then restart is it dead? or cranks right up? I'd stay close to the place you launch when you try it or have a person back you up for a tow.

 

[Matuszak24]

I don’t usually have to return to the dock. Just sit in the water for a couple of minutes. It always fires back up. I just ran a voltage test and at 5500 rpm’s and it got up to 13.5 volts