okay guys, it seems that a lot of '03 wr owners have joined the forum with starter related problems. for the new guys, you have probably gotten into one of the hottest topics involving the '03 wr450. i'll see if i can condense some of it. the '03 starter system is a one way design for the most part. if the motor tries to go "backwards" the starter design wont let it. sometimes it was from a small back fire. sometimes from just shutting the motor off. most, if not all, of us have heard the odd noise these bikes make when you shut 'em off. there was supposed to be a little slip in the idler gear1 but it seems to be a bit lacking. it looks like more and more owners are finding that when the flywheel and idler gear wont slip, the side cover supporting the other idler gear is breaking. go to the search feature of this forum and type in "letter" or "letters". check out the posting by BlueOne about "wr450 check this out". he had pictures of his broken side cover. some of us are hoping we can get yamaha to respond to this problem. you might want to take a look at the splined shaft of your starter. it seems like a few of the owners with broken side covers are finding that the hardened surface of the shaft is chipping away also. your dealer may be able to warrenty the cover through the local yamaha rep as a courtesy but that does not fix the cause. good luck.