GT55 Parallel Key Shaft - O.S. Engine OS29708200  [OS29708200]

Parallel key for GT55 engine assemblies

This O.S. Engine parallel key is made for GT55 RC engine applications. Hardened steel construction transfers torque between crankshaft and flywheel or clutch hubs while keeping rotating parts indexed to prevent slippage under load.

Installation is straightforward: align the shaft keyway with the mating hub, slide the key into the slot until it sits flush or slightly proud depending on hub clearance, then secure the flywheel and verify smooth, wobble-free rotation. Inspect the key after high-rev sessions and replace it if you observe any deformation.

Use the key as a fixed mechanical datum to ensure repeatable timing and orientation during tuning. Avoid forcing the key into an undersized slot; a gentle tap or light press is usually sufficient. This item is supplied as a practical replacement or spare for routine RC engine maintenance.