Daelim Motor Corporation DMC made pedal and no-pedal moped engines 1984-1990, on US model Trac mopeds.
Daelim DP50 info sheet
DP50 upgrades: In 1987 two things were improved.
1) The change lever E13-9 was upgraded to a cable-less type. The start cable and start lever below the left handlebar were eliminated.
2) The gear set E7B-3 and E8B-13 was upgraded. Gear E7B-3 has a rounded square center hole. The four engage balls move inward (to disengage the motor for easy pedaling) and outward (to engage the motor) into the four corners of the square hole. These gears crack at one of the corners, when the engage process is not done gently. The upgraded gear set has 3? more teeth on the E7B-3 gear and 3 less on the mate gear E8B-13. More teeth made the E7B-3 gear thicker at the four corners where it was cracking at.
Driveshaft gear E7B-3 changed from #13009 (24T) to #18750 (27T?).
Idleshaft gear E8B-13 changed from #13019 (23T) to #18751 (20T?).
Daelim DP50 driveshaft gear E7B-3 24 tooth
more to follow…