This 2006 KX250F has been a bundle of frustration for me so far. I got it last Sunday, used obviously. I take the seat off and the filter deteriorates in my hands. I buy a new filter but the bike pops A LOT. I replaced the spark plug and now it hardly pops and only during decel. But yesterday was trouble. I rode 10 to 20 laps and find out my kickstarter fell off and the bolt broke off with it so I couldn't bolt it back on. But it still started, so I rode it all day in 70 degree weather. Not too hot. I start my bike for a final few laps, put it in neutral, throw my helmet on and shift down to go. The bike locks up on me. It won't kick. Pretty much seized without riding it. I'm just wondering if it seized like that could it just be the top end? It didn't blow up while riding it. I just wanted to see if it could be a freak accident and I don't want to spend a whole bunch of money with a mechanic... Any ideas?