My RM 125 Suzuki dirt bike motor is wore out! I have a RM 250 motor but, will it interchange? I wouldn't mind have a little more power. Its a late 70's bike i do believe, that's something else i need to determine. How do i find the actual year of the bike? I'm the third owner, so no papers with it, just as is but complete. How hard will it be to get parts for it if needed?