It all started last week when my YZ 250 started to have this erratic rev pattern after letting off the gas. After it was warmed-up and you let off the gas after a hard acceleration, it would idle strong, erratic, and hard on the way back down to the lower rpm's until it died. Anyway, it gets worse. Took her out to the track yesterday evening, and after an hour's worth of hard laps, I noticed it was running louder than usual. I know, I know, I should have pulled over. However, I was trying to pass somebody and kept it pinned UNTIL she locked-up. The kickstarter will not even move. How much should the bill be (best and worst case). The cylinder is definitely scored, right? Should I go ahead and bore it out if it the cylinder wall is trashed? How much more would it cost to bore it as compared to having the cylinder repaired?