You can get additive's for unleaded to make it leaded. Most people use it in old cars, that run on leaded gas. I think it would work on a moped, but i don't know if it would mess with the 2cycle oil or not. you can get this at napa or autozone (any car part stores in your town) maybe even at a gas station! I dont think you should run the unlead if it tells you not too. some people will run the unleaded gas in stuff that say it needs leaded gas wich is not a good idea. it will mess up the motor some how, or won't run good. Just go down to your town car parts store and ask them they should help you out. I think the stuff is called "insted of lead" or something like that.
well, good luck!!!!