Hatroi HA215 Engine Shaft Flange Compatible with #643 #644 and YS4C-63~70 OS4C-70~81  [HA215]

Replacement flange for RC engine shafts

This Hatroi HA215 flange is engineered as an RC-scale replacement for the specified reference part numbers and engine identifiers. It is suitable for #643, #644 and engines listed as YS4C-63~70 and OS4C-70~81, reflecting the fitment details presented in the product name.

Use the flange to replace a worn or damaged mounting flange and restore correct shaft engagement. The component is intended to maintain concentric alignment between the engine shaft and prop or coupling devices and is for hobby model glow engines only.

Installation notes: check that the seating surface and fastener holes match the original item, clean mating faces before fitting, and tighten fasteners to the torque values recommended by your engine or model documentation. After installation, assess axial alignment so the shaft turns true before routine operation.

Tuning role: installing a correct-fit flange can lower runout and vibration at model scale, helping you spot true throttle and idle characteristics during setup and running sessions.