It all started with the following symptoms: Moped would die when you put the accelerator in the middle range, especially right after starting. Then the moped started dying after riding it for a little while. It acted like it ran out of gas. Not sure if the two symptoms are connected
We drained the tank. (tank is in good shape) cleaned the fuel lines and the petcock. The problem still persisted and maybe got worse. I also had put in carburetor cleaner somewhere along the line. Now gas has started dripping from the carburetor!
So now I've taken the carburetor out. Parts of it are pitted as if someone had soaked it in acid! A previous owner had epoxied the float tank, so this isn't a new problem.
The carb seems to be made of some kind of cast alloy. My dad thinks that it was designed before unleaded fuel was common (1978 Vespa Bravo) and the unleaded fuel (which contains methyl alcohol) corrodes the alloy. However, I've never seen anyone mention anything in this forum about not being able to use unleaded gas, is this really a problem with older mopeds?