My YZ250F 2003 wont start anymore

[tim_tam1785]

Hey guys, so the other day i was riding my yz250f and it was all good until i tried to jump a log. after i jumped it i stalled it but didn't drop it and it didn't wanna kick start anymore. so me and my friends tried roll starting it then it sounded like it was running but had no power. we tried a couple times and it just rolled down the hill and sounded like it was running but when i pulled the throttle nothing would happen. I was wondering if maybe it had something to do with the spark or spark plug but im not sure. what do you guys think?

 

[Rich Rohrich]

The four-stroke Yamahas use an FCR carb which has an accelerator pump unlike the CV type carb you see on XRs and similar lower performance bikes. It's difficult to wet foul a plug with a CV carb engine, but it's relatively easy with the high performance FCR carb. It's fairly common to stall these bikes and then wet foul the plug trying to restart it. This is especially true on a hot engine. Don't bother trying to clean the plug, start with a fresh plug and let us know how it goes.