O.S. Engine OS22512000 Crankshaft 25AX replacement for RC engine maintenance  [OS22512000]

Crankshaft for 25AX engines

This crankshaft is an RC-scale replacement part designated by the O.S. Engine model code OS22512000 and intended for use with 25AX-series O.S. engines. The text below focuses on fitment, installation considerations, and its role when servicing or tuning small nitro RC powerplants.

Fit and compatibility: confirm the engine model stamping or manual to verify the 25AX designation before installation. The crankshaft is supplied as a single rotating assembly intended to replace a worn or damaged unit during an engine rebuild. Inspect mating surfaces and the crankcase seating area for wear and correct alignment prior to assembly.

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

Tuning and maintenance role: as a service part, the crankshaft is central to restoring mechanical integrity during mid-life maintenance, supporting consistent rotation and timing for carburetion and ignition setups. Replace the crankshaft as part of a comprehensive rebuild when internal wear affects performance or reliability.

Use this part when restoring or maintaining O.S. 25AX engines, and follow standard engine rebuild checks to ensure correct fit and reliable operation.