i just purchased a gamefisher 7.5, 1976, per the seller it has been in a garage for over 25 years. i took it home, replaced the fuel lines and installed a fuel filter and the engine started on four pulls. it is air cooled but i see that it has a water pump to cool the lower tower, should i replace the impeller due to sitting in a dry state and the fuel cutoff valve is stuck in the open position. can this fuel valve be rebuilt with a seal or packing, and where can i get parts? thank you very much for any responses. this is my first post on this forums.