.038 MFD @ 12 V.
Capacitor will not stop fire unless shorted. You can use an OHM meter to check resistance or simply un-hook the lead from the coil and check fire.
The right side magneto [alternator] doesn't supply very much at kickstart speeds, and often weak magnets on the end of the camshaft make matter much worse.
I send all my side-cover ignitions to Dave in AZ. to rebuild.
Good luck on the coil as it is worth a small fortune. Often a "used" one will bring over $300.00.
Don't rule out the points, as the clip that contacts the coil can have a bad connection.
Have fun,