Flying Horse 66cc/80cc 2-Stroke Motorized Bicycle Engine Crank Shaft &ndash; Gas Bike Lower Crank Shaft Replacement This Crank works within most 66/80cc bike engine kit motors to crank the piston within the cylinder in order to fire your Flying Horse, Mega Motors, Grubee, RAW, Stinger, or Power King Bicycle Engine Kits Installation will require disassembling of the entire engine and splitting the crank case. Once split, locate the old crank and remove the piston and piston pin (and crank connector bearing if applicable). Install the piston assembly on to your new crank, install the crank in to the case, and reassemble the engine Note: If your engine has bushings you will need to purchase an additional crank connector bearing in order to use this crank. Crank does not include crank connector bearings or spare piston accessories