Re: saw chopper bikes on youtube and had to get one :)
My OCC Stingray was my first, and so far only motorized bike build done at age 12. It seems like the bike is never really "done" because there is always something that you want to change, add, or make better. I bought the engine mount, and exhaust from Barry on ebay. I did not need a sprocket adaptor, it just bolted right to the hub. If you get a Stingray with only rear brakes, like mine, then I recommend getting a front brake as well which is one of the things I still have to do.