Few years ago I took the side cover apart to chase an electrical problem, bike didn't want to start. Life got in the way and the bike got put in a corner.
Now I want to make it run again but somehow it is missing the small gear between the starter motor and the flywheel. Anyone has a schematic or a part number so I can buy a new or 2nd hand one?

 

What year is the machine? Year and model are always need when looking for parts.

 

It's an early one, no reverse gear. But I don't have the serial number, previous owner did competition with it, and the chassis is painted red...