I'm having a problem with my bike, happened 2 days now and I'm stumped. 2009 KLX250S with 8,000 miles. Bike starts and runs great. But after riding 7 miles, the bike dies. No warning, no spudder, just engine stops running. Doesn't matter what speed or rpm range. Headlight, dash panel, both stay on, no flicker and doesn't dim at all. Roll to a stop, it starts up, and runs fine for a minute or so, then cuts out again. Sometimes it's dead for a few seconds, sometimes a minute or 2. Starter always cranks over. At first, I thought it was fuel related or water in my gas. Starts, goes a few hundred feet, dies, and will repete this over and over. But the longer it sits after it dies, the longer it runs until it dies. Last week I removed the tank, carb, and all fuel lines. Tank is a 3 gal IMS with a plastic cap. Not vapor lock, cap vents very well. Cleaned carb, removed all jets, etc, float level is right at 16mm, perfect, clean. No issues found with carb at all. Nothing in tank, petcock cleaned and flows. Replaced all hoses with new. Air filter is clean. So button it up, go out again this passed Sunday, same exact thing happened. And right at the same mileage. Ran perfect until around 7 miles. Then bam, cuts out like hitting the kill switch. So now I'm thinking electrical. My kickstand switch and clutch switch have been bypassed for a year now. I checked all the wiring, and connections on almost the "whole" bike. Battery ground, everything I could think of. Like I said, no power loss, just engine shuts off instantly and intermitently. But after running 7 miles. So now I'm thinking electrical and heat related. I tested stator and OK. I need help guys. I was a motorcycle mechanic and wrenched in dealerships for 20 years. But haven't done so in almost 20 years, so I'm rusty and forgot alot. I covered the basics I think. Plug looks OK, etc. Going to test coil and CDI today. But wanted to post this before I go out to the shop. I'm really stumped here. The good thing is, its all on video. You can see it happen as if YOU were riding my bike, from the camera view, chin mounted video. It dies for the very first time at 7:09 (time on left) into this video. The first time I tried to start, it wasn't in neutral. So it looks like battery is dead, but not the case. Never lost power. Battery is brand new 2 months. Not running hot. Both days were cool at about 55 degrees.

Here. At 7:09



Really stumped here, need your help.

Thank You

 

On my older suzuki, it had points/condensor ignition. The condensor went bad, did just what you describe. The condensor would fail when it got warmed up. But I don't think these bikes have a condensor, sorry.
I would look at a overheating component in the CDI or a swap out?

 

Have you got the stock tank? If so put it back on and see if that makes a difference. It sounds like a venting problem to me.

 

That is my guess too.

Try cracking the fuel cap open a little bit. The check valve might have gone bad.

 

Its NOT a venting issue. Cap was loose, cap vents VERY easy both ways. Its a plastic cap with a clear, clean straight open hole with clear clean hose. I even blew into hose pressurising the tank. Trust what I said above in all I inspected, cleaned, rebuilt, etc. I do know this stuff well. I'm just stumped cuz I'm missing something or not seeing something.

 

Yes, I was thinking stator, then CDI. I bench tested stator as the factory service manual shows. It tested OK and even tested each coil section to ground for a short and tested OK. I'm thinking CDI now and from my passed experience, either the CDI works, or it doesn't. Not for a short period then stops working. But yes, I'll have to test this. I could be totally off on that thought. Thing is, if I test it while it's working, I'm thinking it will test good/OK. I'd have to test while it's cutting out in order for test to Fail. Just my thoughts though. Here's my problem. CDI costs $450 bucks, and there are NO RETURNS on these types of electric parts. It can be easily shorted out and damaged, so no one will accept returns. And at $450 to buy on a "maybe", I just can't do that, period. IF its for sure the CDI, it will take me some time to save up the money. I have to figure a way to do a complete test on CDI or find someone to loan me one to test. I don't know anyone else with a KLX. None in my area. I belong to all the FaceBook groups in my area and there are no KLX owners. My area is 90% KTM riders.....

 

Stator is my first thought. Sometimes they can short when hot but test just find cold. The key would be to test is as soon as the bike dies. Of course easier said than done.

 

I found an acquaintance with an '07 to check my CDI. It was bad (my mistake during wiring in some accessories). Then found a used one on ebay for around $150.

Any chance of finding someone nearby with a KLX? We tested my bad CDI on their good bike and didn't want to risk putting their CDI on mine as I wasn't 100% positive the wiring issue was resolved.

Can a coil cause this problem?

 

items in store on eBay!


now sure what year bike you have but this ebay store has a 2009 cdi for 120 dollars buy it now.

 

The symptoms really do sound like a fuel/venting issue as Maverick suggested because of the absolute consistency in the results. Even with heated up failing in electrical components, you usually don't get this kind of consistency. With fuel, it usually runs out at about the same rate in most cases and therefore the same timing. While you checked the cap venting...and you're right about the aftermarket tank and cap being pretty well idiot proof for diagnosis...are your carb vent tubes fully open? Though it would be odd for both bowl vent tubes to get closed/clogged at the same time, I've seen them melted or pinched simultaneously and also clogged at the same time because of a mud event. I've also seen a situation where one of those weird little dirt dauber-like bugs builds a clog inside both carb vent lines during warmer weather.

Now, as far as the electrical possibly, you're absolutely correct that this could be the issue. It seems you've done a great deal of proper diagnosis on the components you can test. And yeah, unfortunately those tests will often only reveal the component's condition while cold and not hot. You've been pretty thorough, and you may only have the option of testing and elimination by parts swapping at this point. This is why I'd beat the fuel delivery issue/possibility to death before going further. I'd go so far as to set the bike up outside in a level position with a large gas catch under the bowl drain tube. Turn the petcock on and let fuel drain as fast as it will drain for a decent period to see if you get a stoppage. With the cap and everything in place as in normal riding condition, you should see if anything interrupts the fuel delivery into the carb with this test. That should pretty much eliminate the fuel delivery issue.