Info on a 2002 CR250

[cnrcpla]

Liquid weld can fix that  That stuff fixes everything...   

[Swimr2DaResQ]

Ran into another issue today, the carb has been giving me hell trying to get it dialed in, or so I thought! The bike idles great, and will run on the stand all day long and revs to the moon. It's getting plenty of fuel and air, it's still not dialed in to where it should be but it's good enough to start plug chops. Rode it around the yard for a bit and never really cracked it open(yard is not big enough for that), so after she is all warmed up and seems to be breathing fire again I head out on the street to open it up and wind through the gears. First is somewhat smooth and the power winds up quick, shift into second and crack it open again, it winds up strong until about halfway through the powerband and starts to die off like its not getting fuel, I let off the gas and pull in the clutch, it idles really high then starts to jump up in rpm's, let the clutch out a little and brings the idle back down, crack the throttle open and it sputters and dies. The carb is emaculate at this point every thing but the slide and body are new, and set to fmf jetting specs for an 02. I can sometimes run it through the gears up to 4th without opening the throttle all way. A buddy of mine that had a little pitbike with a fourstroke motor in it had a similar problem. His bike would die under load in the same manner that this cr250 is doing, put his bike on the stand and it runs great, idles and revs to it's limiter no problem. He went through every option, even replacing his carb. He heard a few guys on forums talk about possible electrical issues, so he chased the electrical system starting at the plug all the way back to the stator/alternator. He replaced everything through that system and found the problem was the alternator/stator. When the bike was not under load it performed as expected, under load and on the go the stator could not provide a strong enough spark to combust the air/fuel mixture in the cylinder. So, I am wondering if anyone has ever had issues with this sort of problem on their 2strokes and am I way off in assuming this to be a problem or possibly on the right track!
Any help would be greatly appreciated!
thanks,
Chad

[metal_miracle]

yes i have had same problem but it was the main jet that was to small

[scooter042]

unplug kill switch and take it for a ride.
Fastest cheapest check for random dying. It has happened to me. Chased things for weeks and got scared to do jumps on it. new switch and all good.

[gpnewhouse7]

One of my mates used to have a 2005 cr250 that ran good on the stand and ran good on tick over but would almost die if you revved it and he found it to be the powervalve as the previous owner had took it out an put it back in upside down. After he fixed it he had to sell it because it had too much power for him.