Flying Horse 66cc/80cc 2-Stroke Motorized Bicycle Engine Cylinder Body Cap &ndash; Gas Bike Cylinder Head The 80cc Angle Fire Cylinder Body Cap is an angle fire head cap made for 66/80cc 2-stroke bicycle engine kits To install simply unbolt the existing studs, lift off the cap, replace the head gasket (if necessary), torque down the head, and you're ready to run 6mm Head Studs; Torque: 9-12 lb/ft