YOUNG PROPS boat propeller 14x21 4-blade 15-tooth RH for Mercruiser Alpha/Bravo One — aluminum, hub kit included

The YOUNG PROPS 14x21 4-blade aluminum propeller is a right-hand, 15-tooth replacement designed to restore performance on Mercruiser Alpha/Bravo One drives and Mercury 135–300HP outboards.

This aluminum propeller pairs a 14-inch diameter with a 21-inch pitch and four blades to balance top speed, acceleration and handling for recreational and work boats. Built from alloy-aluminum and inspected under strict quality controls, it substitutes for OEM reference 48-8M0084496 and suits a broad range of Mercury and Mercruiser applications. A complete hub kit and installation hardware are included to make swapouts straightforward.

What engines and drives will this propeller fit?

This prop is intended for Mercruiser Alpha and Bravo One drives as well as many Mercury outboards in the 135–300 HP range. Check spline/tooth count and rotation to confirm compatibility before ordering.

• Designed for right-hand rotation (RH) applications.
• 15-tooth spline matches specified lower units and drives.
• Common replacement for OEM 48-8M0084496 reference numbers.
• Suitable across many Mercury/Mercruiser models within 135–300 HP.

How does a 14x21, 4-blade design affect performance?

The combination of 14-inch diameter and 21-inch pitch provides a compromise between straight-line speed and pulling power. Adding a fourth blade increases bite in turns and improves acceleration, helping when you’re accelerating with heavy loads or towing.

• 21-inch pitch targets higher top-end speed without extreme slip.
• Four blades smooth thrust and reduce ventilation in rough water.
• 14-inch diameter maintains usable ground clearance and cavitation resistance.
• Alloy-aluminum construction keeps weight down for responsive feel.

What comes in the box and how easy is installation?

YOUNG PROPS ships this propeller with a full hub kit and all required hardware to replace the original unit. The included components let most mechanically competent owners complete the swap with basic tools and the proper torque sequence.

• Interchangeable hub and drive sleeve for secure fitment.
• Forward thrust washer, aft adapter, tab washer, and propeller nut included.
• Installation typically requires standard sockets, pliers, and torque wrench.
• Follow manufacturer torque specs and safety steps when installing.

How durable is this propeller and what warranty is offered?

Manufactured under strict quality control, the alloy-aluminum blade construction emphasizes durability while aiming to preserve engine rpm and fuel efficiency. A 12-month replacement policy covers blade fractures and hub bush slippage under normal use, with common exclusions for misuse or modification.

• Alloy-aluminum resists corrosion and delivers long service life.
• Designed to reduce engine wear by keeping efficient rpm characteristics.
• 12-month replacement for specific failures (excludes normal wear and accidental damage).

Who is this for?

This propeller is suited to recreational boaters, anglers and small commercial operators who need a direct-fit replacement for Mercruiser Alpha/Bravo One or compatible Mercury outboards in the 135–300 HP range. It’s a good choice if you want a four-blade option that improves acceleration and handling, comes with a complete hub kit, and offers a straightforward swap without custom machining.