Starter idler gear shot to pieces

[jave101]

Had a bit of spare time on my hands so I decided to have a look at why my starter motor was free spinning as my kick starter is starting to stuff up.
Thought it would be a simple job, just replace the starter clutch components.

That didn't happen, the idler gear was installed back to front so when I pulled it off I found it had no teeth at all and the starter motor shaft was all chewed up.
Any body know what could have caused this and more importantly where I can source some new parts?

I'm thinking about removing the engine from the frame because I need to replace the rings too unless it is possible to remove the cylinder block with the engine in the frame?

[Badooka]

Dang that is some seriously bad metal! And yes you can change rings with the engine in the bike. No problem at all. Try Z1 Enterprises or maybe get lucky on Ebay with a good used one! Don't forget to adjust your valves whilst in there as well.

[jave101]

Anyone know what could cause this?
I assume the previous owner knew about this because the idler gear was installed upside down.
I'm thinking it could be from the bike not being tuned properly and backfiring.

Anyway new parts are on their way. Just hope it doesn't happen again.

[Mekanix]

Da-f% happened to that?


I have no idea unless there was one broken tooth to begin with from a single backfire.

Then everytime the starter winds the gear around to the same spot it will skip and slam the next tooth until that one breaks and then it just continues until they are all gone.