Tohatsu & Nissan Outboard Propeller Chart
Propellers have two basic dimensions; diameter &
pitch. Diameter is the distance measured across
the propeller hub line from the outer edge of
the circle that is made by the propeller's
blades during rotation. Pitch is the distance
that a boat will travel if rotated one
revolution without any slippage. When describing
a propeller both the diameter and pitch are
given. The diameter is referenced first and the
pitch is second. Therefore, a 12" x 9" propeller
would have a 12-inch diameter and a 9-inch blade
pitch.
Theoretically, a propeller with a 14-inch pitch,
when rotated one full turn, would advance a boat
14 inches through the water. In reality, no
14-inch pitch blade will advance a boat 14
inches with one full turn. This variance is
referred to as slippage.
In general, changing to a higher pitch prop will
increase your top-end speed but reduce your
acceleration (reduce your "hole-shot" power). On
the other hand, decreasing the pitch will
increase your hole-shot but sacrifice some of
your top-end speed. If the hole-shot speed is
important to you, for example if you pull water
skiers most of the time, then you would want to
go with a lower pitch prop and sacrifice some of
your top-end speed but increase your hole-shot
speed to get the skiers up faster.
UNDER NO CIRCUMSTANCES SHOULD YOU EVER USE A
PROP WHICH WILL ALLOW YOUR OUTBOARD TO OPERATE
ABOVE THE OUTBOARD'S RECOMMENDED MAXIMUM RPM's!
The propeller selection chart can be used to
help you in selecting the correct propeller for
your Tohatsu outboard. Remember that in any
application, discrepancies in performance can
result due to the different boat hull designs,
the final carrying load and your particular
needs.
NOTE:
It is highly recommended that the outboard be
checked with a tachometer to ensure that the
engine is operating within the correct MAXIMUM
RPM RANGE.
The selection of the correct propeller
will allow the engine to obtain it's full
RPM as well as the designated horsepower.
Engine horsepower is very closely related
to the RPM that the outboard can obtain.
In other words, if the outboard can not
reach its specified RPM, it cannot reach
its specified horsepower.
We hope that this selection chart helps
you in making the right decision when
choosing a propeller for your Tohatsu
outboard.