ALUMINUM PROPELLER 15.3X21 LEFT 48-13703A46

Function and technical context

The 15.3×21 left-turn aluminum propeller is the propulsion element that transforms the power of the Mercury engine into direct thrust to move the boat. Coupled to the propeller drive shaft, this propeller works within the propulsion system, being responsible for the efficient transfer of rotational energy from the crankshaft to the water. Its specific 15.3-inch diameter, 21-inch pitch geometry has been designed to balance rapid acceleration and fuel efficiency in cruising, making it critical to maintaining performance and fuel economy. A failure in the propeller or its progressive wear causes loss of traction, vibrations in the transmission, increased consumption and a significant reduction in maximum speed.

When to replace this part?

Aluminum propellers suffer erosive wear due to cavitation, impacts with submerged objects and marine corrosion, presenting symptoms such as abnormal vibrations during acceleration, progressive loss of maximum speed, metallic noises in the transmission or dry knocks when changing gears. It is recommended that the propeller be inspected at the beginning of each boating season and replaced if it has warping, cracks, visible blade erosion or structural damage, as a deteriorated propeller not only reduces performance but can cause imbalances that damage the drive shaft and bearings. Preventive replacement of a worn propeller avoids costly repairs to the propulsion system and ensures safe navigation.

Equivalent manufacturer part numbers