Aluminum Propeller 9.3x10R for 9.9-20HP (Higher Pitch for Speed)

The 9.3x10 aluminum propeller is a high-performance option for small outboards (9.9-20 HP), aimed at increasing your boat’s speed under lighter load conditions. With a 10″ pitch (versus the typical 8″ on a standard prop), it lets the engine push the boat faster at a given RPM. For instance, if you run a 15 HP motor on a light boat and the stock 8″ prop has the motor screaming at high RPM, switching to this 10″ prop will reduce the RPM at the same speed and raise the potential top speed. Even so, acceleration remains adequate for most situations, especially when the boat isn’t overloaded.

This prop is compatible with multiple brands – including Yamaha, Selva, Parsun, and even some Mercury/Mariner models – that use an 8-spline shaft in this horsepower class. The high-quality aluminum build and three optimized blades ensure smooth running and minimal vibration. The propeller is coated to resist corrosion, protecting it from rust during saltwater use. It mounts directly in place of the original – no special tools or alterations needed. If you’re looking to get more pace out of your boat without changing the engine, this propeller is one of the easiest and most effective ways to do it.

• Ideal Applications: Small RIBs and hard boats (3 – 4.5 m) with 9.9-15 HP engines, when the boat is operated with a light load or for quick trips. Example: a 10 HP engine on an inflatable boat that, with an 8″ prop, hits max RPM at moderate speed – with a 10″ prop the boat will travel faster at full throttle, enabling quicker transit over the water.
• Recommended For: Boat owners who want lower engine RPM at cruising speed and potentially better fuel economy. With a higher pitch, the engine runs more “relaxed” at moderate speeds, meaning less wear and noise.
• Swap According to Conditions: You can use this prop as a “sport” option for days when you want speed (e.g., flat water runs). On days with heavy loads or for watersports, you might switch back to a 9.3x8R prop for extra thrust. Having both options gives you the flexibility to tune your boat’s performance to your needs.
• Compatibility: Its 8-spline hub makes it compatible with Yamaha 9.9-15 HP 4-strokes and 9.9-20 HP 2-stroke models (series with code 63V, etc.), Parsun/Hidea 9.9-20 HP, Selva, and even some Mercury/Mariner 9.9-15 HP units (from periods when they used Japanese gearcases). This covers a wide range of engines, meaning you can upgrade the performance of many different boats with this single propeller.