Multi-d Aluminum Propeller AMITA4 12.50X19 Right Hand 2413-125-19

Function and technical context

This four-blade aluminum propeller, with a diameter of 12.50 inches and pitch 19, acts as the final propulsion element in the outboard drive transmission, converting engine torque into hydraulic thrust on the water. It operates in the stern drive propulsion system, being the component that closes the kinematic chain between the bevel gear, the propeller shaft, and the aquatic environment. Its right-hand rotation configuration makes it suitable for standard single-engine installations, ensuring thrust in the correct forward direction. The cast aluminum absorbs moderate impacts with a degree of controlled deformation, protecting the shaft and transmission from sudden loads. A propeller with incorrect pitch or deteriorated condition directly compromises the engine performance curve, preventing design rpm from being reached and increasing fuel consumption per nautical mile.

When to replace this component?

The clearest signs that the propeller requires inspection or replacement are: appearance of noticeable vibration in the transom or tiller at different engine speeds, evident reduction in top speed or difficulty in planing with normal load, excessive cavitation reflected in an irregular and foamy wake, and visible physical damage to the blades such as cracks, bends, or material stripped away following contact with the bottom or submerged objects. It is recommended to inspect the propeller at each seasonal haul-out and after any impact, checking the pitch and blade balance. Immediate replacement of any pitch deformation avoids transmitting abnormal stresses to the shaft seal and bevel pinion, preventing stern drive failures that cost far more than the propeller itself.

Equivalent manufacturer references