I have a model PC0422505.02 Coleman portable generator, powered by a Model 122K02, 5hp Briggs & Stratton engine. This engine seized and I am trying to disengage the engine from the rotor of the generator. I removed the bolt from the crankshaft but it will not disengage. Can you give me some tips on the best way to break them free. I am reluctant to use undue force, Thanks Dale Boyce