What I did to check the spark and ignition system was to remove the magneto cover and spin the crankshaft with an electric drill. I modified an old 1/4" socket extention , put a socket on it and then spun the motor with an electric drill. Works great. It sure beats pedaling. The big problem I found was the OEM spark plug connector. The brass insert can unscrew itself and lose current. I lopped it off and soldered on a ring connector to the HT wire and screwed the electrode barrel connector on to secure it. I also cut two slots on top of it so it can be installed and removed with a screwdriver. There's an old drag racer's trick for improving a plug's spark; use a Dremel or file to round the hanging electrode to match the profile of the core electrode. The spark gets concentrated into the shortest distance of the gap.