Selecting the Yamaha Propeller That’s Best for You

Are you looking to replace or upgrade your Yamaha propeller? Our “Outboard Propellers – Engineered for Performance” article covered the basic engineering characteristics of a propeller. Even a casual reading will allow you to conclude that every inch and angle—even its material—makes a difference in the way your Yamaha propeller influences your boat’s performance.

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This article dives a bit deeper into the Yamaha propeller selection process, including taking a quick look at Yamaha propeller families and their typical applications. In addition to the information included in this article, the Yamaha Propeller Selector is an invaluable tool. PartsVu carries the full line of Yamaha propellers, so after inputting all of the needed information, you can simply head back to PartsVu.com and search for the recommended Yamaha propeller part number.

Yamaha Propeller Selection

As you begin your outboard propeller selection process, think about the type of boating you do and whether your current boat propeller pitch and diameter are helping or hurting performance.

Generally speaking, boaters are trying to improve one or a combination of the following factors:

• Over-revving at Wide-Open Throttle (WOT)
• Failure to reach optimum RPM at WOT
• Hole-shot and acceleration
• Inability to reach top speed
• Fuel economy
• Ventilating or cavitating

Maximizing Horsepower, Minimizing RPM

The right propeller for your boat and engine combination is based in part on the wide-open throttle (WOT) operating range for your specific engine. This information is an intersection of horsepower and RPM and can be found in your owner's manual.

An optimal outboard propeller will maximize your boat's performance while allowing your engine to operate in the recommended RPM range. The correct propeller will prevent the engine from over-revving and facilitate maximum horsepower with minimum RPM.

An outboard engine under load should reach the manufacturer’s recommended RPM at WOT, usually expressed as an RPM range. Your optimal propeller will deliver acceptable acceleration and top speed while still allowing your Yamaha outboard to reach its recommended revs at WOT.

If you get this relationship wrong, premature engine damage is too often the result.

Outboard Propeller Considerations

Your propeller decision-making process will include the following factors: boat propeller pitch, diameter, aluminum or steel, blade number, rake, cupping, and rotation.

What is boat propeller pitch?

Boat propeller pitch is the distance a propeller would move forward in one full rotation if there were no slip in the water. For example, a 19-pitch prop is designed to move 19 inches forward per revolution. Pitch is one of the most important prop choices because it directly affects engine RPM, acceleration, and top speed.

Boat propeller pitch explained in 3 points:

1. Lower pitch = easier to spin → higher RPM, faster hole-shot, lower top speed
2. Higher pitch = harder to spin → lower RPM, slower hole-shot, higher potential top speed
3. Pitch that is too low over-revs the engine; pitch that is too high bogs the engine and can cause long-term damage

Propeller pitch (boat prop pitch explained)

Propeller pitch is a critically important factor when selecting a new prop. It’s the distance a propeller would move forward in one full revolution with no slip–so a 19-pitch prop is designed to travel 19 inches per turn.

• Lower-pitch propellers encounter less resistance, so they spin faster and give better hole-shot and acceleration. The trade-off is lower potential top speed because each revolution covers less distance.
• Higher-pitch propellers move the boat farther with each revolution, which can increase top speed, but they’re harder for the engine to turn. Acceleration is slower and RPM drops.

Generally speaking:

• Increasing prop pitch lowers RPM
• Decreasing prop pitch raises RPM

If you choose a pitch that’s too high (“over-propping”), the motor won’t have enough horsepower to turn the prop effectively. RPM will drop below the recommended wide-open-throttle range, which overloads the engine and can cause long-term wear. If the pitch is too low (“under-propping”), the engine can over-rev, hurt fuel economy, and shorten engine life.

Lower-pitch propellers encounter less resistance facilitating faster rotation and enabling hole-shot and acceleration. However, because each propeller revolution generates less forward travel, the ultimate top speed will be lower at WOT.

Hole-shot and acceleration will be reduced with higher pitch props because the outboard propeller encounters more resistance. This said, additional resistance reduces the motor's RPMs and top speed at WOT.

Generally speaking, increasing prop pitch lowers RPM, while decreasing prop pitch raises RPM.

If you need more speed, a higher pitch is generally the way to go. However, If you use a propeller with a too high pitch, the motor won't have enough horsepower to turn it adequately, so the revolutions per minute will drop. Referred to as over-propping, it overloads the engine and causes excessive wear. Under-propping—fitting a propeller with too low a diameter or pitch—can damage your engine through over-revving. Under-propping will also adversely affect fuel consumption.

How to choose the right propeller pitch for your boat

Signs your boat propeller pitch is wrong

• Engine easily hits or exceeds max RPM at WOT → pitch likely too low (under-propped)
• Engine struggles to reach recommended RPM, feels “luggy,” or takes a long time to get on plane → pitch likely too high (over-propped)
• Great hole-shot but disappointing top speed → pitch may be too low for your performance goals
• Good top speed but very slow acceleration → pitch may be higher than needed for your typical load

A simple way to think about pitch selection is to start with your current WOT RPM:

• If your engine is over-revving above the manufacturer’s recommended WOT range, you likely need to increase pitch (or diameter) to bring RPM down.
• If your engine cannot reach the recommended WOT range, you likely need to decrease pitch so the engine can spin more freely.

Most prop changes are made in 2-inch pitch increments, which typically changes WOT RPM by roughly 300–400 RPM depending on the setup. Always compare your actual WOT RPM–loaded as you normally run–to your engine’s recommended range in the owner’s manual.

Prop Diameter

Each outboard propeller has two numbers stamped on them – diameter and pitch. For example, a 14 x 19 propeller has a diameter of 14 inches and a pitch of 19 inches. The greater the diameter, the more resistance it will experience in the water.

A larger diameter propeller reduces the RPM and top-end speed. On the other hand, smaller diameter propellers increase RPM and top-end speed. However, smaller diameter props slip more frequently and are not good choices if hole-shot or acceleration improvement is your goal.

Aluminum or Steel

Aluminum propellers are the most common and the least expensive. Stainless steel propellers are more durable and generally perform better due to both thinner and stiffer blades.

Number of Blades

Most commonly, propellers have either three or four blades. Three-blade propellers are most common on general use recreational boats. With only three blades in the water, they encounter less resistance increasing fuel efficiency, and they generally have minimal impact on your outboard engine's RPM.

Four-blade propellers improve hole-shot acceleration; therefore, commonly used on ski boats. These props improve handling and are generally better in rough water.

Propeller Rake

Propeller rake is the angle that the blades slant backward. The higher the rake angle, the more the boat's bow lifts out of the water. A high rake angle reduces time to plane and increases top-end speed. However, if a rake is too high, the outboard motor will operate under strain and experience premature wear.

Cupping

A cupped propeller includes a curved lip to the trailing edge of propeller blades. It will get better traction in the water, reducing prop slip and ventilation, and improves hole-shot and acceleration. Cupped props allow the engine to be trimmed so the propeller is closer to the water's surface and can dramatically reduce RPM.

Propeller Rotation

Rotation is not an issue for most boaters as most outboards rotate the propeller shaft and propeller clockwise. However, a few run counter-clockwise, especially in dual outboard setups in which one motor runs clockwise, and the other runs counter-clockwise for better balance. Make sure your selected prop is designed for the correct rotation.

Yamaha Propeller Families

With a discussion of many outboard propeller characteristics covered, let’s look at Yamaha's propeller lineup by application and general boat classification.

Small & Medium Boats

Reliance

Created specifically for high-horsepower, in-line four-cylinder outboards (F150, F175, and F200). It’s faster at all RPM ranges than Yamaha’s painted stainless-steel propellers and resists ventilation. It features a new SDS design that needs no special hardware to function.

Talon SS

Smooth, quiet shifting, and trolling for F70 – F115 and T50/T60 outboards on pontoon, walleye, fiberglass, and deep-V boats. They feature an updated SDS design that requires no special hardware to function.

Aluminum

Low-cost and lightweight, it provides good overall performance for outboards 2 HP to 225 HP, and a wide variety of applications.

Family & Watersport Boats

Reliance

The Reliance family of outboard props is also great for many family boats pulling towables and boaters who participate in watersports.

Talon Pontoon

Excellent low-speed operation, providing higher thrust and control than conventional propellers on pontoons (even heavily loaded) using T50-F115 outboards. Features an SDS design that requires no special hardware to function.

Dual Thrust

Harnesses the power of Yamaha’s high-thrust outboards for pushing heavy loads such as sailboats and pontoons, and provides outstanding reverse thrust. Standard on T9.9 and T25, optional on T50 and T60.

Bass, Bay & Flat Boats

V MAX SHO

An ultra-high-performance ventless design and single-inch pitches allow you to fine-tune the performance of Yamaha’s four-stroke V MAX SHO.

Pro Series

This stainless-steel series provides high performance for single-outboard boats requiring bow lift.

Talon SS4

Stronger hole-shot than comparable 3-blade propellers. Excellent on mid-range powered flats boats or for applications requiring high engine mounting heights. Fits F70 to VF115, T50/T60 K series (4.25") gearcases. Standard Shift Dampener System (SDS).

Large Boats

Saltwater Series II

Designed for larger offshore boats, it provides more extended cruising range, superior midrange fuel efficiency, and better handling in rough seas. Features a new SDS design that requires no special hardware to function.

Saltwater Series XL

Designed for the V8 F350 four-stroke outboard, these propellers provide plenty of power-to-plane, acceleration, and top-end. The updated hub system accommodates older Yamaha F350s.

XTO OS Propellers

With diameters from 16 to 17 1/8 inches and increased blade surface, XTO OS propellers are engineered to complement the torque potential of V8 XTO Offshore outboards on 50-foot and larger boats. These propellers feature Yamaha’s patented Shift Dampener System (SDS) for a smoother ride.

Frequently Asked Questions

What is prop pitch on a boat propeller?

Prop pitch is the distance a boat propeller would move forward in one full turn with no slippage, typically measured in inches. It affects how hard the engine works, how fast the boat accelerates, and your potential top speed.

How does boat propeller pitch affect RPM?

Lower pitch lets the engine rev higher (like a low gear), while higher pitch reduces RPM (like a high gear). Increasing pitch generally lowers WOT RPM, while decreasing pitch raises it.

How do I know if my boat prop pitch is wrong?

If your engine over-revs past the recommended WOT range, the pitch is likely too low. If it cannot reach recommended RPM and feels sluggish, the pitch is probably too high. Comparing your loaded WOT RPM to your engine’s spec is the best test.

Is higher prop pitch always faster?

Only if the engine can turn it within the recommended RPM range. Too much pitch can bog the engine, hurt acceleration, and actually reduce top speed.

If you are considering replacing or upgrading your Yamaha propeller, we hope this information helps. As mentioned at the beginning of this article, the Yamaha Propeller Selector is a valuable tool that is extremely helpful.