hello,i would check the mag for spark.
the coil in the mag cause a fair bit of trouble.
ckeck jets in the carbie and filter in the fuel line were it connects to the carbie.
pull the bowl of the carbie and blow out the two jets.to check to see if it is ok use compress and blow air up the venturi from undernethe the blow and have some fuel in the bowl.fuel shoud be drawn up the venturi.
if it your mag you can have the coil tested and fixed