Small, drive gear.
Buzzing down a deserted main st at 3AM, I lost all thrust but engine noise was about the same but free-wheeling like whine. Took clutch cover off and the small, drive gear seemed to have moved out and away from the engine and towards the pedal and could be turned by hand. Next day for the life of me I could not get the motor apart. Any advice on getting nut under spring to turn? took off plate on other side and used 2 wrenches but was close to rounding both nuts. Will try penetrating oil tomorrow, but not sure that's a great idea. I tapped small gear back inward with rubber mallet and bike started and ran a few feet then same no go, no bad sounds. (Not all bad)
Biggest bummer is it is the engine off "ol red" AND SUMMER IS HERE!
This will be the first time I have seen the inside, where all the Chinese, Happy Time happens.