I am a proud BME fan, but I wanted to throw another name in the mix that is at the VERY LEAST comparable to all the others mentioned........TAURUS----the Taurus TS52 is a 52 cc engine that isn't the lightest in it's class, but is definitely the SMOOTHEST. Actual weight is similar to the other 50cc engines. I ran a SIDE-BY-SIDE comparison with this engine to my BME50 and they were both on the money with the same props.....tried about 6 different props including a 19x10 3 blade. Both engines were BRAND NEW.