Motor Sprocket Shaft Key for Harley FX & FL 1956–1980 – Replaces OEM 23985-56

This motor sprocket shaft key is designed to secure the engine sprocket to the motor shaft on Harley-Davidson Big Twin models.

The key fits into the sprocket shaft keyway and prevents the engine sprocket from rotating independently of the shaft. Proper key fit is critical for maintaining correct primary drive alignment and preventing damage to the sprocket and shaft during operation.

Designed for FX models from 1971 through 1980 and FL models from 1956 through 1980, this key is intended for stock-style engine sprocket and shaft applications used during engine or primary drive service.

This part replaces Harley-Davidson OEM 23985-56. At Boomers Bike Shop, we stock drivetrain components that fit correctly and are trusted for real Harley-Davidson service work.

Fits Harley-Davidson Models:

FL: 1956–1980

FX: 1971–1980

⚠️ Designed for stock-style motor sprocket shaft applications.