This kit includes what you need to convert your downhill gravity trike into an engine powered beast.  
Kit includes
Custom offset Go-kart wheels and tires
1 1/4" Tubular steel axle
Cassette Style axle bearings
Weld-on Bearing brackets
Lightweight Axle hubs
Lightweight Sprocket hub
Racing split full-tooth go-kart sprocket
#35 RLV Extreme Chain
Heavy-duty clutch
1 Set of PVC "Slider Sleeves"
*Does not include engine*
*Does not include braking system, not required, but I would highly recommend getting some sort of stopping power*
I know picture has brakes in it, but it is not included.  I need an updated picture.