Actually, some of the Arctic Saxonettes were the 2.8 horsepower version. Not slow at all. They aslo made a way slower restricted version around 1.5 hp which may be which ones you have seen Sir Rebel. I have used the engines before. The same case in Europe held a 2 speed or a 3 speed handlebar shift. I also had a 2 gang that I dropped the 2.8 horse cylinder onto once which really ripped.