The motor on my '03 YZ450f recently seized. It busted the piston and cylinder and bent the valves, etc., etc. I may have a chance to pick-up a motor complete with Carb, CDI Box, and all motor wiring except for the kill switch from an '05 YZ450f for a decent price. Will this fit on my bike? Are there any parts that are not compatible between the two different year bikes? What are some questions I should ask about this motor before I purchase it? I am strapped for cash, so I'm looking for every less expensive option than to pay $2000 to fix mine. Thanks.