So I recently purchased a 2001 YZ250 with no Engine. I am looking to make it in to a single track enduro bike. I am right now looking for some what of a complete engine and have come across one recently pulled motor out of a 2011 yz250. To my knowledge the only thing different about the motors from pretty much 99-Present is the swing arm pivot. I guess they changed sizes in 02. I was wondering if anyone knew if it is possible to interchange that 2011 engine into an 2001 frame?