i heard they don't last long and i want to get ride of manual clutch all together and add pull start. I would have better made parts and was think how to mount it in replace of manual gear clutch that way case is not wider. There kit replaces crank sprocket with the cent. clutch gear . Was reading that it's ok but not the best. It seems to be cheaply made heard a lot of bad things about boy go fast and friend got motor and it's a dog slow. I reset carb runs better. Just was think there is got to be a better way to make it . Was thinking also of making a belt drive kit for these since it makes ride smoother thanks for you info. Maybe there kit with a better cent. clutch would work out better .was watch video the way they have kit mount on crank to replace crank sprocket. Make the cent. clutch spin but that the wrong way to do it the outer case should only spin as throttle is giving. So why would you want that to happen then motor wants to jump out from under aybe or die out .