BRAND NEW!!! KX250F front sproket snapped in HALF


It has stumped most of the riders that were there. My son's new 2006 KX250F, that he had only 6 hours of ride time in, snapped the front sprocket in half while riding it. We have the bike down at the dealer and they are stumped as well, they are going to bat for us at Corporate Kawasaki, who has requested to see the sprocket and chain, so that has been sent to Kawasaki for their techs to inspect the sprocket. Curious if anyone out there has heard of or knows of this happening to any other 250's. Other than this mystery of a sprocket, my son has long awaited to ride his 250 and loved every minute of the six hours he rode it.

yeh thats wierd, i have about 4 on mine right now, lol 2 to go too see where i sit lol.

Thankfully, yes.....except for the fact that I forgot to mention.....I believe when the chain snapped it whipped the case cover right in front of the sprocket and cracked it....the crack is on the top, I am hoping it is just a cover that can be replaced

im sure they will take care of it for you. I think kawasaki cares alot about its customers and their contigency benefits show it.

I have never heard of a counter shaft sprocket breaking....interesting.

I'd like to see a pic of that one. I've seen rear sprockets munched but never seen a front one break in half. Only seen a front with no teeth and that was on a real beater. The only thing I can think of is it cracked when they stamped it out, but that is a complete guess. Any pic?

Send me an email at and I will send you the picture or if you could tell me how to post the picture for everyone to see


Send it to me, as well as the name of the dealer and Kawasaki's regional service rep that's handling it, if you wouldn't mind.

I believe Sunstar is making countershaft sprockets for most of the Japanese manufactures these days. Out of all the millions of bikes out there, they are bound to have a defect sooner or later.

The chain most likely snapped first and slammed into the case and behind the front sprocket and caused it to break. That makes sense.

I would also be in school of thought that the chain caused the problem more so than the sprocket.

If it was a chain snap that put enough force on the countershaft sprocket to break there is high potential for other things on the countershaft itself to be damaged. If it snapped the sprocket it probably locked up the transmission and put some serious load on everything. It is probably worth it to split the cases and inspect the tranny.

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