Yes, let's do get our terminology correct.A quick test would be to, take out plug, Plug it back into boot, lay it on engine head for ground, give it a kick and check for spark. If the plug is grounded good you will get spark, unless the COIL is bad. PLEASE FOLKS, get the guy started in the right direction by intsructing on the proper use of names for parts. a coil is not a magneto. The MAGNETO is the oblong spinning MAGnet inside of the COIL.
The coil is not part of the magneto, nor is it in the engine. The coil is the component that has the spark plug wire coming out of it. Usually it is a separate part, but the coil in these engine kits is built into the CDI housing (the black box that mounts to the frame of the bike).
Under the timing cover of the engine is a spinning magnet that is attached to the end of the crankshaft. That spinning magnet is called the rotor. Surrounding the rotor is a U-shaped piece of steel with a spool of wire on it. That part is the stator. The spool of wire is the stator winding (not the coil; calling it a coil confuses the issue). The rotor/stator/winding combination is the magneto.