My GT750J is one of the early ones--with the 9 degree roller engagement angle on the starter clutch. This original design starter clutch likes to slip although it improved quite a bit when I started running Amsol dirtbike transmission oil. So as a winter project I decided to install a later style starter clutch that employs 7 degree roller engagement angles. (The starter clutch updates are covered in Service Bulletin #4--attached)
When I pulled off the old starter clutch I found this. It must have happened right toward the end of the season before I laid up the bike for the winter. There were no ill effects during the season and no suspicious noise. Also, there was no metal in the bottom of the engine and there was not galling or pitting on the bearing running surface on the crankshaft.
Is this a particular flaw of the old style starter clutch? Interested in comments.
That is an unusual mode of failure and looks like a roller split. I would just get a new roller bearing and slip it in - as long as the bore of teh starter clutch is still OK
