Guess it's luck of the draw. Grandson had one put in is go-cart as a replacement engine. It crapped the bed soon afterwards. Have you seen the reviews on the Chinese-made Coleman mini-bikes? Baaaad news. I'd love to see at least an American mini-bike made as good and simple as the Rupp and Bonanza. They may be more expensive, but you'd think enough people wanting longevity, reliability and American would sustain the market.