Flying Horse 48cc/66cc/80cc 2-Stroke Motorized Bicycle Engine Clutch Arm &ndash; Gas Bike Clutch Arm Replacement The Clutch Arm is helped by the clutch cable for your 2-stroke 48cc or 66/80cc motorized bike engine in order to engage and disengage your motor Installation may require special tools: lift the clutch arm off of the clutch camshaft. Once uninstalled, replace with this clutch arm, press the arm down on to the shaft, and you're ready to ride