96 GTX Bogging Down at 5000 rpms.

[camaro_hodges]

I have a 96 GTX, that starts up fine and revs up to 7000 out of the water, but then about 1 minute later, it will only rev to 5000 rpms and it sounds like it is bogging down. I have rebuilt the two carbs twice, made sure the high rpm screw was in. Any ideas, on what to do next? I have had the carbs off twice to make sure the rebuild was good and the diaphragms were not torn. Thanks for your help!

 

[nswillin]

Pull the sparkys and give it a compression test to make sure. Check all fuel filters and lines. If all is good there try adjusting the carbs.
LOW SPEED SCREW 1.5 ± 0.25 TURNS
HIGH SPEED SCREW has cap that allows an adjustment of 1/4 turn.
Turning screw 1/4 turn counterclockwise enriches mixture and turning screw clockwise leans mixture. Do not attempt to adjust high speed screw by removing plastic cap.

 

[timmyboy76]

ummm....low speed setting calls for 1 turn out, and high speed is 0...if this dont work, try disconnecting red wire from rectifier. Did you do popoff test and after carb assembly, do carb pressure of 4lbs, make sure didnt leak??

 

[nswillin]

Yeah your right, your so smart, I looked at wrong one. :banghead::banghead::banghead::banghead:

 

[timmyboy76]

nah, just looked at the right one....:rofl:...lol

 

[camaro_hodges]

So I cut the red wire on the rectifier, and it seems to work fine. So now what? Do I need to replace the rectifier?

 

[timmyboy76]

yep...this is why...
..The rectifier/regulator box does two things. It recieves AC voltage generated by the stator coils through the yellow wires. It then converts that AC power to DC power using the rectifier portion. The red wire sends back to the battery, regulated DC voltage to keep your battery charged while riding the ski.
When the rectifier quits working, that red wire is sending AC voltage to the DC battery. Your ignition runs off DC power as it is a DC CDI ignition. When AC is sent, it interferes with the DC CDI. If you can picture the static your car radio has when under high power lines you can understand how the AC effects the ignition.

A magneto produces very little voltage at lower rpm and more voltage at higher rpm. That is why the motor will start and run decent at lower rpm, but run very ragged at higher rpm when the rectifier is shot..:cheers:

 

[camaro_hodges]

I went and bought a used rectifier and put it on and it works fine. The guy I bought it from has been working on jet skis for 20 years and swore that could not be it, but if it is, to call him back and let him know for future reference. Thanks for the explaination. I would have never figured this one out. Much thanks!

 

[96GTXtom]

Did this work for repairing the problem?