24621-921-010 Shaft Bush - Overview. The 24621-921-010 Shaft Bush is an essential component within Honda marine engine systems. This shaft bush functions primarily as a wear-resistant sleeve that supports rotating shafts, reducing friction and wear to ensure smooth and reliable mechanical motion. Designed to fit seamlessly within the marine engine's rigging and accessories, it plays a critical role in maintaining proper alignment and preventing excessive vibration or damage to other mechanical p