O.S. Engine OS22512000 Replacement Crankshaft for 25AX  [OS22512000]

Fitment and compatibility notes for 25AX units

The crankshaft is identified by O.S. Engine model OS22512000 and is intended for use with 25AX-series O.S. engines. The text that follows outlines compatibility checks, installation considerations, and the component's function when servicing small nitro RC engines.

Fit and compatibility: verify the engine's stamped model code or consult the service manual to confirm 25AX compatibility before installation. The crankshaft is supplied as a single rotating assembly to replace a worn or damaged original during a rebuild. Inspect the crankcase seating area and mating surfaces for signs of wear or misalignment prior to assembly.

Installation notes: when replacing the crankshaft, check crankpin bearings, seals, and clear oil passages of debris. Ensure correct endplay and bearing preload per the engine service data. Rotate the assembly by hand after initial assembly to verify smooth movement before the first run.

Tuning and maintenance role: as a service part, the crankshaft reinstates consistent rotation and timing necessary for stable carburetion and ignition adjustments. Replace it as part of a comprehensive rebuild when internal wear affects engine performance.

Fit this part during full rebuilds of O.S. 25AX engines and perform all standard service checks to ensure correct fit and reliable running.