US Patent 7004134 Engine generator

A positioning pin is knocked onto a crankshaft of an engine and a key way is formed in a boss of a first flywheel. When an outer rotor type generator is connected with the engine, the boss of the first flywheel is fitted over the crankshaft so as to adjust the positioning pin to the key way. When an inner rotor type generator is connected with the engine, a rotor shaft on which a rotor of a generator is mounted is fitted to a second flywheel so as to adjust the positioning pin to a key way formed in the second flywheel. The ignition angle of the engine is determined by fitting the positioning pin to the key way.