So, I've read thru every single thread I could find that could possibly contain an answer to my issue, both here and over at Thumpertalk... so I'm posting it as a new topic!

My '09KLX250S (which many of you have helped me out with before) is now acting up in a very strange way that it never has before. For the past two months or so, the bike has been mainly sitting in my shed for the winter season, but I've been firing it up here and there and done a few short rides to make sure it stays in shape. Back a few months ago, I dropped the bike real hard on the Slickrock trail out in Moab, and ended up busting one of the notorious shift star pins. Other than being a pain to wait for the parts and ripping everything apart, and finding a new shift lever, it really wasn't too big of a deal... she's shifting better now than ever before, much crisper and more distinct shifts (I now have the newer start gear design).

When I was out on a ride (on the road) about a month ago, out of nowhere at all, the bike began to sputter under throttle (EXACTLY the same feeling as when throttling the bike too much when it's still warming up from cold). I instinctively began to baby the throttle and keep it running, but slowly it just sputtered to a stop... AND the computer flashed off and on and reset at the same time. My immediate reaction was that the battery was acting up. I was able to get it started again, but shortly down the road it stalled again in the exact same way (computer reset again), and I was never able to get it started again (not even with a roll start). For the past couple weeks, out of frustration at having yet another issue, I stuck to snowboarding and let the bike sit in the shed with the battery trickle charging, half hoping it would mysteriously heal itself!

So, fast forward to this past weekend... after doing every test I could on the battery with a mutimeter (non-conclusive, as everything read correct during a load test) - I took it to O'Reilly and Advance Auto to have them test it... O'Reilly guy said it was fried, and the Advance guy said it was fine (but didn't seem too confident). I tried starting the bike straight off the original battery, jumped it off of a car battery (with my battery removed), and also jumped it from a plug-in jumper box. I was never able to get it started again with just the battery itself, but when plugged into the car battery or jump box, I could get it to start about 75% of the time... but after idling for awhile she would just poop out slowly again... the computer reset most of the time, but not EVERY time! So I just decided to pick up a Bike Master replacement gel battery and try it out. This afternoon I installed the new battery, said a prayer, and fired her right up! it ran for a few seconds, I killed it, restarted it, fired it back up, and figured I was good to go... but as soon as I gave it the SLIGHTEST bit of throttle it died out again just like it had been. However, the computer has never reset so far when stalling with the new battery installed.

As I said, my initial impression was that it was a battery issue right off the bat, but I was/am also very su****ious of there maybe being a loose ground or electrical connection somewhere. I still haven't begun to gut the bike and check out all of that stuff, but that's what I'm about to start here in a minute. I'd really like to know if anyone can help me with suggestions on where to start though! Electrical weirdness (computer reset, etc) notwithstanding, I could also see it being a carb issue... but that makes no sense in terms of explaining the electrical crap. It also doesn't seem to me that it would be the magneto or anything like that, given the strange and varying symptoms. The fact that the computer only resets some of the times when it stalls seems to me to support the fact that it could be a loose connection somewhere.

Up until now, my bike has NEVER failed to start up right away, never stalled, and it has always run totally flawlessly.

Help, anyone??

CHEERS,
Jon W.

 

UPDATE: I have been trying to do measurements on the rotor, stator, and voltage regulator according to the service manual, but I can't get the damn thing to run long enough (or throttle it up to high enough RPMs)... it still starts every time on the first try, after it has been sitting for awhile... but it just idles for a few seconds, sometimes more, then fades out and stalls. After that first start, I can never get it to start again right away (I've tried it with the new battery, old battery, plugged into jumper box, and plugged the bike straight into my car battery as well... it'll crank forever and not turn over). Another interesting point... the computer DOES NOT reset every single time it stalls anymore... very strange. Other than the computer resetting, I guess there isn't really anything that should lead me to believe it's an electrical problem... maybe this whole thing is just being caused by a strange blockage in the carb or fuel lines? Whatever it is, it's driving me bonkers!!!

 

I'm no expert on matters like this but it sounds like an electrical problem to me. I'd check all the connectors from the instrument panel all they way back to the battery. Make sure all the cables have a little give and aren't binding or pinched. Check all your fuses and make sure the battery cables are tight.

 

U sure its not the carb? I've had similar issues when condensation built up in the gas before... except for the computer resetting stuff, I have no idea what your talking about concerning that stuff. Does the display just flash or something?

 

I would start with the fuel and a new plug then if it dies again pull the plug to see if its wet or dry. I hate ethanol!
marc

 

My suggestion is if you find a condenser anywhere... on the ignition or charging system, change it. Sometimes they fail when heated to operating temps, but at cold temps work fine. Sometimes the plug can do the same thing if it is cracked.
If the float on the carb is not working right, the carb will fill, it will run on the fuel, then it can't fill up fast enough again, causing the engine to die.
I think you may have had two issues, 1. a bad battery 2. another issue.

 

See if you can keep it running w/ starter fluid.



.

 

There are four engineers traveling in a car; a mechanical engineer, a chemical engineer, an electrical engineer and a computer engineer.

The car breaks down. “Sounds to me as if the pistons have seized. We’ll have to strip down the engine before we can get the car working again”, says the mechanical engineer.

“Well”, says the chemical engineer, “it sounded to me as if the fuel might be contaminated. I think we should clear out the fuel system.”

“I thought it might be an grounding problem”, says the electrical engineer, “or maybe a faulty plug lead.”

They all turn to the computer engineer who has said nothing and say: “Well, what do you think?” “Ummm – perhaps if we all get out of the car and get back in again?”

 

Jokes aside, you may have more than one issue.
1. The battery may have been bad. This may have been helped along by a bad ground in your system. Installing a new battery may have fixed both
2. Your carb may need a cleaning. Any junk in the float bowl can get into the carb if you dump the bike just right.
3. Fresh gas & a new plug are easy fixes too.

 

Make sure you have a good ground at the CDI.