GENERAL INFORMATION
36
Propeller Selection
Propping the engine at the higher end of the RPM range may
increase acceleration, but decrease top boat speed. Conversely,
propping the engine at the lower end of the range may increase
top boat speed but hinder acceleration. Mercury Marine
recommends selecting a propeller that allows the engine to
operate in the upper half of the recommended full throttle RPM
range with the boat normally loaded (refer to General
Information - Specifications). This RPM range allows for better
acceleration while maintaining maximum boat speed.
All "L" models (20 in.) and some "XL" models (25 in.) are capable
of operating at engine speeds of up to 6000 RPM. This increased
engine speed gives the operator a greater range of pitch selection.
However, propping at the uppermost limit of the RPM range may
not necessarily result in improved high speed performance. Boat
weight and hull design influence the effectiveness of this increased
engine speed and may decrease top boat speed.
If full throttle operation is below the recommended full throttle
range, the propeller must be changed to prevent loss of
performance and possible engine damage. On the other hand,
operating an engine above the recommended operating RPM
range will cause higher than normal wear or damage. Generally,
there is a 200-300 RPM change between propeller pitches.
If changing conditions cause the RPM to drop below the
recommended range (such as warmer, more humid weather,
operation at higher elevations, increased boat load, or a dirty boat
bottom/gearcase), a propeller change or cleaning may be required
to maintain performance and ensure the outboards durability.
To Next Page
Loading...
Need help?
General
