APC AP04742 Propeller 4.7x4.2E Electric (Speed 400 Motor) spare propeller  [AP04742]

4.7x4.2E Propeller for Speed 400 Electric Motor

This APC AP04742 propeller is an RC-scale replacement designed around the 4.7x4.2E designation and the Speed 400 electric motor family. It serves as a direct spare for small electric-model applications where that motor class is used, and its form factor focuses on straightforward swap-in replacement and simple tuning tasks rather than performance claims.

Installation is typical of small electric propellers: confirm the prop fits your prop adapter or shaft size on the Speed 400 setup, secure with the appropriate retainer, and ensure the prop direction matches your motor rotation. After mounting, perform a static check at low throttle to verify secure fitment before full-power runs.

For tuning and maintenance, check the blade edges and hub for any nicks or cracks and replace the unit if damage is visible. Simple balancing with a prop balancer or a manual center-point check can reduce vibration and make throttle response steadier on small electric models.