Page 4 - Yamaha Marine Marine Zubehör 2019

Propellers

Propellers and Propeller Accessories

PROPELLER INFORMATION
THE PROPELLER MAKES ALL THE DIFFERENCE.
If you haven’t tried one of Yamaha’s comprehensive range of 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 speed, 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.
Pitch
Pitch is the distance (in inches) a particular prop would theoretically 25 Pitch - 5200 RPM PITCH
travel in one full revolution, as if traveling through a solid. A lower 23 Pitch - 5600 RPM
pitch will have better hole shot and “pushing power” but a lower top 21 Pitch - 6000 RPM Pitch is the 'theoretical' distance (in inches) a propeller would travel in one full revolution, if it were
speed, while a higher pitch prop will provide less acceleration, but a travelling through solid matter. A prop with low pitch will deliver better acceleration/hole shot and
greater potential for higher top speeds. The correct propeller will
allow your engine to reach the upper portion of the WOT range pushing power but a lower top speed, while a higher pitch prop will provide less thrust, but with
speci ed by the manufacturer with a normal-to-heavy load (without a higher top speed. The correct propeller will allow your engine to reach the upper portion of the
exceeding it). Each inch of pitch is equal to approximately 150 +/- 50 W-O-T range specified by the manufacturer with a normal-to-heavy load, but without exceeding it.
RPM.
Each inch of pitch is equal to approximately 150 +/- 50 RPM.

DIAMETER Diameter
Diameter means the total width of the “circle” at the blade tips as the propeller spins. Larger
Diameter means the total width of the “circle” at the blade tips as the
propeller spins. A larger diameter pushes more water and reaches
diameter props push more water and reach deeper down into the water, so they're typically used on
deeper into the water, so they’re typically used on large, heavy boats
large, heavy boats or ones with higher-placed engine mountings. A smaller diameter prop is usually
or ones with high engine mounting heights. A smaller diameter is
usually used on lighter weight boats, where the prop operates lower
used on lighter boats, where the prop operates closer to the surface of the water - or when you
in the water or when a gain in engine RPM is desired.
need a higher engine RPM.
NUMBER OF BLADES
Number of Blades
Three-bladed propellers are the most common, o ering good overall Three-bladed propellers are the most common, offering good overall performance, top speed, and
performance, top speed, and e ciency for most applications. Four efficiency for most applications. While a four-bladed prop will provide increased bow and stern-lift
blades characteristically provide increased acceleration, enhanced
bow- and stern-lift, and reduced ventilation. However, four blades and reduce prop ventilation, this normally means more drag on the engine, resulting in lower top
typically mean more drag on the engine, resulting in lower top speeds and different handling characteristics.
speeds and di erent handling characteristics.
BLADE GEOMETRY
Blade geometry refers to the actual shape of the blade (or ear). By manipulating the blade’s shape, Blade Geometry
diameter and pitch progression, different performance characteristics can be created for each Blade geometry refers to the actual shape of the blade (or ear). By
manipulating the blade’s shape, diameter and pitch progression,
different type and style of propeller. di erent performance characteristics are created for each di erent
type and style of propeller.

BLADE SURFACE AREA
Blade Surface Area
Blade surface area refers to the total surface of the blades. The more Blade surface area refers to the total surface of the blades. The greater the blade surface area, the
blade surface area a prop has the more water it pushes, for better more water the prop pushes, for better hole shot and increased planing efficiency. However, too
hole shot and increased planing e ciency. Too much can create
signi cantly more drag, however, potentially restricting engine RPM much blade area can create significantly more drag, potentially restricting engine RPM and causing
and causing negative boat-handling issues.
negative boat-handling issues.
CUP
Cup
Cup is the small curved lip on the blade tip and/or trailing edge. Used in proper amounts, cup helps Cup is the small curved lip on the blade tip and/or trailing edge. Used
reduce ventilation and propeller slippage, allowing for higher engine mounting and greater bow lift. in proper amounts, cup helps reduce ventilation and propeller
slippage, allowing for higher mounting heights and greater bow lift.
However, too much cup may cause excessive steering torque and bow lift - and limit the engine’s Too much cup, however, will cause excessive steering torque and
bow lift and limit the engine’s ability to develop and maintain proper
ability to develop and maintain proper RPM at a certain pitch. RPM at a certain pitch.

2 – Marine accessories