It would have been easy to just part the bad bike out for spares, but a second option also existed: rebuild this engine with a 60cc cylinder kit to replace the bad piston and cylinder, and turn this engine into our high performance motor. FA50 engines are easy to swap so we could keep our original FA50 road worthy, get this engine prepped, and swap it into our old bike. The old, stock engine could then be swapped into the second FA50 and we would end up with two complete bikes and succeed in both of our goals. The only real change to our engine plans here was buying a 60cc engine kit. We originally wanted to keep our FA50 as a 50cc bike, but a 60cc swap would repair the damage inside our second engine. We are refreshing our engine from air filter to exhaust, so let’s run down our new bits from suck, to squish, to bang, to blow.