I got the kids a couple of doodle bug bikes for christmas, and they are having a blast on them. The motor is way to weak to carry me (225lb) up any kind of slope. I mentioned that I would like to put one together that I could play around with the kids on. A few days later my wife shows up with an Intek 206 5.5 with a 6 to 1 gear reduction box, that she got a good deal on. I figured I would just remove the box and put a centrifugal clutch on and go. When I pulled the box off, it has a splined shaft. Is there a clutch that would go on that type of shaft? Would it just be best to put the box back on? I know it would pull like crazy, but I want some speed too. Any advice would be appreciated. Thanks.