Mercury 135 Verado FourStroke, Руководство по эксплуатации и обслуживанию

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The following are some propeller basics that will help you determine the correct
propeller for your boating application.
Diameter
‑ The diameter is the distance across the imaginary circle that is
made when the propeller rotates. The correct diameter for each propeller has
been predetermined for the design of your outboard. However, when more than
one diameter is available for the same pitch, use a larger diameter for heavy
boat applications and a smaller diameter for lighter applications.
Pitch
‑ The pitch is the theoretical distance, in inches, that a propeller travels
forward during one revolution. Pitch can be thought of similar to gears in a car.
The lower the gear, the faster the car will accelerate, but with lower overall top
speed. Likewise, a lower pitch propeller will accelerate quickly, but top‑end
speed will be reduced. The higher the propeller pitch the faster the boat will
usually go; though typically slowing acceleration.
Determining the correct pitch size
‑ First, check the full throttle RPM under
normal load condition. If the full throttle RPM is within the recommended range,
select a replacement or upgrade propeller with the same pitch as the current
propeller.
• Adding 1 inch of pitch will reduce the full throttle RPM by 150 to 200
• Subtracting 1 inch of pitch will increase full throttle RPM by 150 to 200
• Upgrading from a 3‑blade propeller to a 4‑blade propeller will generally
decrease full throttle RPM by 50 to 100
IMPORTANT: Avoid damage to the engine. Never use a propeller that allows
the engine to exceed the recommended full throttle RPM range when under
normal full throttle operation.
PROPELLER MATERIAL
Most propellers manufactured by Mercury Marine are made from either
aluminum or stainless steel. Aluminum is suitable for general purpose use and
is standard equipment on many new boats. Stainless steel is over five times
more durable than aluminum and typically provides performance gains in
acceleration and top end speed due to design efficiencies. Stainless steel
propellers also come in a larger variety of sizes and styles that allow you to dial
in the ultimate performance for your boat.
3 BLADE VS. 4 BLADE
Available in many sizes of both aluminum and stainless, 3 and 4‑blade
propellers have unique performance characteristics. In general, 3‑blade
propellers offer good all around performance and higher top speed than
4‑blade propellers. However, 4‑blade propellers are usually faster to plane and
more efficient at cruising speeds, but lack the top end speed of a 3‑blade
propeller.
GENERAL INFORMATION
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