So I recently bought a real nice 2000 CR250, the bike is in great condition and the engine just got rebuilt 8 hours ago. I took it out yesterday and rode trails for about 45 minutes before we jumped on some logging roads. I was careful not to push the bike to hard so I kept it the lower end of 4th gear most of the ride. Anyway at one point I put the bike into 5th and got on it for probably 30 seconds before the back wheel completely locked up and sent me skidding. The engine shut off till I was almost to a stop then started working again. The rest of the day the bike had great compression (starting first kick everytime) and rode completely normal. Ive read a lot of forums thay say this kind of thing is a siezed engine but im just curious to get some other opinions of what might have happened.