I bought this used for my son about 2 years ago with hopes he would be interested in it, but it just hasn't worked out. Comer C-51 engine. I put new piston rings in and gaskets. I also added a NKR carbon fiber pedal risers. It was used by my son about 4 times. There are 2 sets of rims/tires with the kart, but I would say not all 8 tires are usable at this point (4 between the 8). A homebuilt, foldable kart stand is also included.  Can also include a racing jacket, neck brace and rib protector.