We can offer you this woodruff key from Motoforce in OEM quality.
Its function is of course to flywheel onto the crankshaft in the correct position, thus ensuring the right ignition timing

This is one of those small fiddly parts that are easily lost or stuck in the old crankshaft, make sure you have a spare!

Here's a useless fact, the woodruff key was invented in the late 1800's and named after the Woodruff Manufacturing Company!

This is universal and fits virtually all 50cc 2-stroke mopeds except Peugeot.

Dimensions:
12x5x3mm (length x depth x width)

Motoforce MF60.16615