Any pictures of the sisters? You need three things present, to run. Fuel, ignition, compression. Your motor has a carburetor, so looking to see if fuel is present should be easy. Pull a sprak plug, place it back in the plug wire, ground the body of the plug to the mptpr, and have a sister crank it over. You will see the plug spark, or not. The timing belt can jump, and often does, on start up in high mileage poorly maintained vehicles.