The propeller makes all the difference.
If you haven’t tried one of Yamaha’s endless propeller solutions, you’re not getting the most out of your outboard. In fact, the right Yamaha propeller can maximize your outboard’s acceleration, top-end, fuel economy and lifespan, all while providing a quieter ride and better handling. No matter what your application there’s a Genuine Yamaha propeller that can help you achieve peak performance.
Check Your Current Pitch and Size
For a good starting point, check the pitch of your current propeller, marked on the barrel. Your experience with this propeller will be very helpful in correctly selecting a new one.
Consult with your Dealer
Tap into their knowledge to get propeller recommendations based on your boat make, model and year; engine model and identification number. Current propeller size and style; current max RPM at wide- open throttle; and typical and max loads carried. If possible, always test recommended propellers on the water.
Pitch is the 'theoretical' distance (in inches) a propeller would travel in one full revolution, if it were travelling through solid matter. A prop with low pitch will deliver better acceleration/hole shot and pushing power but a lower top speed, while a higher pitch prop will provide less thrust, but with a higher top speed. The correct propeller will allow your engine to reach the upper portion of the W-O-T range specified by the manufacturer with a normal-to-heavy load, but without exceeding it. Each inch of pitch is equal to approximately 150 +/- 50 RPM.
Diameter means the total width of the “circle” at the blade tips as the propeller spins. Larger diameter props push more water and reach deeper down into the water, so they're typically used on large, heavy boats or ones with higher-placed engine mountings. A smaller diameter prop is usually used on lighter boats, where the prop operates closer to the surface of the water - or when you need a higher engine RPM.
NUMBER OF BLADES
Three-bladed propellers are the most common, offering good overall performance, top speed, and efficiency for most applications. While a four-bladed prop will provide increased bow and stern-lift and reduce prop ventilation, this normally means more drag on the engine, resulting in lower top speeds and different handling characteristics.
Blade geometry refers to the actual shape of the blade (or ear). By manipulating the blade’s shape, diameter and pitch progression, different performance characteristics can be created for each different type and style of propeller.
BLADE SURFACE AREA
Blade surface area refers to the total surface of the blades. The greater the blade surface area, the more water the prop pushes, for better hole shot and increased planning efficiency. However, too much blade area can create significantly more drag, potentially restricting engine RPM and causing negative boat-handling issues.
Cup is the small curved lip on the blade tip and/or trailing edge. Used in proper amounts, cup helps reduce ventilation and propeller slippage, allowing for higher engine mounting and greater bow lift. However, too much cup may cause excessive steering torque and bow lift - and limit the engine’s ability to develop and maintain proper RPM at a certain pitch.
Rake is the angle of the blade in relation to the propeller’s barrel, or centre, and is expressed in degrees. A high rake propeller is best suited to applications where the engine is mounted high, to help reduce ventilation and increase bow lift. However, too much rake can strain the engine, decrease hole shot and produce negative performance and handling results. A propeller with a low rake angle will cause less strain on the engine, resulting in potentially better hole shot and higher operating rpm at W-O-T.
SDS – SHIFT DAMPENER SYSTEM
Reducing the annoying shift shock and noise normally associated with moving between gears, Yamaha’s unique Shift Dampening System (SDS) uses a splined aft washer and a splined rubber hub to absorb noise and vibration. This carefully engineered solution brings smoother, quieter gear shifts.