I have the manual right here
first check your kill button make sure its not sticking, then clean all contact points, for example, coil to frame. also check the plug cap, it might be worn. Check your breaker points, they might be worn too, gap should be 0.3-0.4mm or 0.012-0.016in. valve clearence is 0.05mm or 0.002 in and acording to the manual, plug gap is 0.6-0.7mm or 0.024-0.028.
if you need any more info let me know, ive got the whole manual at my disposal, good luck.
P.S The manual gives coil resistance guides in the book on how to test the coil. Ill scan them to the computer tomorrow maybe, good luck.