Hi Tommy

We have the o-rings in stock and can send you some. Changing the o-ring is quite simple:

1) Unscrew the front cover of the starter housing and slide it a little ways down the starter cable.
2) Take a black marker and put a mark on the motor, at the edge of one of the starter housing tangs. This is an easy way to ensure that after you change the o-ring, you can easily set the starter back to the same depth.
3) Remove the starter motor from the housing.
4) Using a small pick or flat screw driver, gently roll the o-ring out of the end of the bendix housing. If you don't have a spare oring handy, you can flip the o-ring over and get a few more starts out of it before needing to replace it.
5) Re-insert the motor into the housing, being careful to line up the marks you made in step 2).
6) Screw the front cover back on the housing.

That's it.

Ed