I believe that his bike uses a 3 phase alternator, not a single winding stator. The ignition is powered by the battery.

Ride on
Brewster

 

Yes very possible. If so you still have a trigger that fires the coil. I would have to see the wiring diagram but you can scope the trigger.

As a auto tech I diagnosis a ton of vehicles with a vantage pro graphing scope . Many are the same story. Died while driving. Of course starts right up off the truck. A scope is my go to tool. Fuel pumps, crank/cam sensors ect. It's the only way. Other wise your just playing (guess again auto) firing parts at it. Customers hate that.

 

It might stick out from below the tank enough for you to see it without taking a video. Be sure to get one with a right angle plug connector. As for the engine running with it, it's just a neon bulb in series with a resister. The bulb could flash but the resister may limit the current to the spark plug.

Before retiring, I was an electronic tech. Thermal or intermittent problems were some of the hardest to solve.

Ride on
Brewster

 

Is this the same schematic as for your bike? Different model and year, but the only schematic I found that has electric start. But, I'm not familiar enough with the various KLX250 models.

http://www.classiccycles.org/media/D...92ffffe417.JPG

Ride on
Brewster

 

If the stator dies the bike wouldn't immediately stop. The bike will run on battery power alone until the battery voltage gets too low to support an effective spark. As the battery gets near this voltage the bike will stutter and jerk as the spark gets less effective.

This sounds like a fuel/venting issue.......haha only joking

It really sounds like an electrical issue, something that causes an open in the electrical circuit once a certain temperature is reached, due to the sudden stop of the motor. Off the top of my head would be ignition coil or the CDI. My advice is to buy a few cans of freeze spray. Run the bike until it fails and spray either the CDI or ignition coil. If it immediately starts then you have found your problem. If it doesn't try the other component.

 

Well by Brewsters schematic it is a two wire crank sensor. That tells me it's not a hall switch. This is simpler and can be metered. This is where I would start it you see your spark tester drop out.

Thanks Brewster

 

It's the KLX250ST9F which is a 2009 KLX250S

Not sure if the one you posted is the same or not.

 

Bang.....Zoom!!!!

To the moon Alice.......LOL

 

Hey there...I feel your pain....I haven't posted here in a while....but you're thread reminded me of what happened to my 09. It would stall when warm after letting off the throttle abruptly. I did a mod to the cdi ground wire....search old posts or maybe someone else can remember the procedure. If I recall I think you cut the ground wire that runs back to the battery (very small gauge) and then ground the cdi directly to the closest bolt. It worked for me a few years back. Good luck!!

 

I'm loving the idea. It's worth a shot. It does kinda start right up, I'd only have about 5 to 10 seconds to do this and thats cutting it close. Hard to tell if it's the freeze, or if it's really working on its own again. Hmmm, quick draw.