stock is stock. but edd still inspects the motor making shure seals are good, orings have no flashings, shims head for the correct timming. and also makes shure everything is withing tolerance.

race prep -inspected then broken in on a speciel break in stand.

modded- lighter crank balanced, lighter piston and rod, timming changes, ceramic bearings, inspected and broken in.
the price is the same for the 21 and 23