Alright guys, First off I'd like to say that i am new to posting but not new to TT as i read it all the time at work. Anyhow, Recently i left my muffler plug in my 2008 YZ250 after washing it, and when i took it out riding the other day i forgot that it was left in and kicked the bike about 10 times until realizing that i left it in. Since then the bike has been acting really weird. After starting it for the first time since the muffler plug was taken out it felt very sluggish and the throttle response was so horrible it made me not want to ride. I shut it off after about 2-3 minuets of it running. I put it back in my garage and went on vacation figuring that i would deal with it when i came back. I decided to kick it after a week after being gone and it started right up and ran great like it usually did. So i went to the track the next day and it wouldn't start no matter how many times i kicked it. I even tried to bump start it and that failed. But i did notice that while trying to bump start it, with it in first gear it was extremely hard to push. (yes the clutch was held in all the way...). Sometimes it will turn over for a few seconds and then it red-lines itself for a brief second with no throttle given and then shuts off. Anyways, my thoughts is that maybe a gasket was blown when kicking it with the muffler plug in? Or does anybody else have any ideas or opinions on this would be much appreciated! I am going to tear it down and do a new top end rebuild and hoping that it solves the problem. I didn't know that a little 6 dollar muffler plug could cause so much trouble.