21q4-20812 21q4-20813 Excavator Throttle Knob R210 Describe: What's typically included The contents of a Zero Switch overhaul kit vary depending on the specific application, but they generally include: Gaskets and Seals: Essential for preventing leaks of fluids and gases between components. Pistons and Rings: Key components for sealing the combustion chamber and controlling oil consumption. Bearings: For the main and connecting rods to ensure smooth rotation. Liners: