XP 96 spark cut at WOT, disconnected rectifier then it works fine BUT..............

[poissonn]

Well usually I can figure out my own problems but right now I'm kinda stumped and I'm not sure where to look at...So here's the thing, the ski starts just fine and revs good on the trailer. Once in the water, it has no problem taking off but as soon as you go WOT, it's seems like spark is cutting out on and off...

My first guess was a bad rectifier so I unplugged the red wire and went for a drive. It worked flawlessly. Ordered a new rectifier and installed it.........the problem was still there. Unplugged the red wire and once again it worked fine just on the battery. At that point I thought it might be a coil/CDI thing or a DOA rectifier. So I swapped the entire front electrical box with the new rectifier in my other XP and guess what, everything worked perfectly, even with the rectifier plugged in...

So basically here's what I've tried so far:

- brand new rectifier (tested good on other ski)
- swapped entire front electrical box in another ski and it worked fine when the other ski was not
- swapped the rear electrical box coil from the bad ski into the good ski and it worked just as good
- removed the MAG cover and checked the pickup coil resistance and if it was still attached
- trimmed spark plug wires & installed new plugs
- compression is 150psi per hole

Now, since when i unplug the red wire at the rectifier the ski runs fine, it HAS to be an electrical problem, right?? The only 2 parts I haven't swapped are the stator and the pickup coil (although it seems good). Can a bad stator cause a weak spark at full throttle? the battery light isn't on btw... I don't want to ditch another 200$ on the ski if i don't have to....anyone got an idea??

 

[Dr Honda]

Did you buy a NEW OEM regulator? If you bought a used unit... or an aftermarket... the new one could be bad.


Check your stator with a meter... and go from there. The regulator should isolate the stator... but if it's shorted... it can cause issues.

 

[poissonn]

Yeah it was a new unit from the dealer. At first i thought it was a DOA so i returned it and got another one. But it was still messing up so I installed the regulator in my other ski to test it and it was good...

I'll recheck the stator with a meter but last time i checked it was within specs. Can it be bad even with good resistances between phases and no short?

 

[poissonn]

Anyone else? I changed the stator for a new one and it still cut sparks randomly at wot...i'm about to throw the ski in the thrash...

 

[Mekanix]

Bad grounds in either electrical box to the engine.
Ground wires on coil not making a good contact.
Cold solder joints on pickup coil.

 

[Dr Honda]

Bad grounds in either electrical box to the engine.
Ground wires on coil not making a good contact.
Cold solder joints on pickup coil.

Yep.


Also... could have a fray wire in the ignition, around the flywheel... and it's touching. Speaking of that... did you pull the cover, to make sure the pickup is in tact, and the wires are OK?

 

[poissonn]

Yeah I had to in order to install the new stator so I checked every wires. Speaking of that, one of my crank seals is seeping oil in the mag cover...Is it bad for the stator and pickup coil?

And where do the electrical boxes ground to except at the battery? i don't remember having to remove any grounds when I pulled the engine last spring...And internally, since the front e-box was put in another ski without problem I don't think there's something wrong with it.

 

[poissonn]

Yeah I had to in order to install the new stator so I checked every wires. Speaking of that, one of my crank seals is seeping oil in the mag cover...Is it bad for the stator and pickup coil?

And where do the electrical boxes ground to except at the battery? i don't remember having to remove any grounds when I pulled the engine last spring...And internally, since the front e-box was put in another ski without problem I don't think there's something wrong with it.

Well i did some further testing. Just a reminder, the stator is new and it isnt short and the resistance are fine. Now what i found is that if i unplug one particular phase of the 3 of the stator it will run just fine. That phase is the only one of the 3 that has a female plug on the rectifier side. Any ideas?

 

[Musicman_L7]

Did this get resolved?? I'm facing a similar issue with the 717 in my 97 GSi. I can ride with the regulator unplugged (which is brand new) but when I plug it in the thing dies repeatedly.