2003 yz450f

[Iceracer07]

Hey guys I have a 2003 yamaha yz450f flat tracker the other day I went to start the kick starter didn't come back up an I cld feel something binding inside so I pulled the kick starter assembly out the shaft an the rachet gear were busted. Any ideas that cld cause this? The bike had a lot of motor work an it is very hard to kick over wondering if it has something to do with it. Thanks