O.S. Engine OS29116208 Precision Valve Pin Screw - 90RSR-M  [OS29116208]

Technical Notes: Valve Pin Set Screw

This part from O.S. Engine is identified as the valve pin set screw for the 90RSR-M designation and is supplied as a maintenance accessory for RC engine valve retention tasks. Use it when your service documentation for 90RSR-M specifies replacement of the valve pin fastener.

The screw secures valve pins to help maintain valve timing integrity after teardown or rebuild operations. When fitting the screw in a workshop setting, ensure the valve train is correctly aligned and threads engage smoothly before final tightening, avoid cross-threading, and check that valves move freely once the engine is reassembled.

For tune-ups and rebuild cycles this small screw plays a necessary role in valve maintenance. When servicing the cylinder head or cam, treat the fastener carefully: begin threads by hand, ensure correct seating, and verify clearances after running the engine.