My Solex has a top speed of 20 mph. I ride all my mopeds at wide open throttle, I mean, even that is not enough. I wish a stock moped would go 40 mph like a stock 50cc scooter. My Honda Metropolitan (50cc liquid cooled 4 stroke) does 40 wide open, and still gets 100 mpg, which is better than any of my mopeds, except the Solex, gets at 30 mph. Of course, a 4 stroke is more efficient than a 2 stroke, but Indian mopeds had 4 stroke engines, and they were the slowest mopeds ever made. It's time for somebody (not the Chinese) to design and build a 50cc liquid cooled moped with a variator that goes 40 mph stock, gets a real 100 mpg, and still looks like a moped. If it can be done with a scooter, it can be done with a moped. (It won't be, but it sure would be nice).