I would remove the spark plugs and see if there is compression coming out both cylinders. IF so, remove the valve covers and see if all is well in there, push rods in place and working. All apparently OK there, remove the cooling shroud and disconnect the Kill Wire from the base of both coils and try the engine. Don't run without cooling shroud.
I can send you a Service, overhaul, Manual for your engine IF you like. Address below, put in proper format and remind me model number and what you want.
Walt Conner