ALUMINUM PROPELLER 15.50X17 LEFT 48-90159A46

Function and technical context

The left 15.50×17 aluminum propeller is the fundamental propulsion element in Mercruiser systems and Mercury/Mariner engines, responsible for transforming the engine power into hydrostatic thrust to move the boat. It works directly coupled to the transmission shaft, where its optimized blade geometry generates the necessary traction through the controlled expulsion of water. Its correct installation and state of conservation are critical: a worn, bent or eroded propeller significantly reduces propulsion efficiency, causes steering vibrations and can cause loss of top speed even with the engine at full load. Additionally, damage to the blades directly affects the balance of the transmission system, generating additional stresses on bearings and seals.

When to replace this part?

The most obvious signs of wear on a propeller include persistent rudder vibration at certain rpm, gradual loss of acceleration despite engine maintenance, audible cavitation (water boiling sound), and visible damage in the form of nicks, cracks or erosion on the edges of the blades. It is recommended to inspect the propeller at least once per boating season and after any impact with a submerged object; Preventative replacement prevents costly breakdowns at sea and ensures maximum propulsion performance. A faulty propeller can overload the engine and compromise maneuverability in emergency situations.

Equivalent manufacturer part numbers