I am repairing a 1978 Puch maxi-luxe for a neighbor boy and need a few questions answered. It says on the ped to use leaded fuel. Is it alright to use unleaded gas? Does the fuel line off the carb go to the front of the bike or the rear in route to the tank. I am repairing this bike for free because the boy doesn't have the money to repair it. He got the bike for free and it is in good shape with 2545 miles on it. What is the estimated value of this bike in case he decides to sell it. Thanks for any help in this matter.