beautypg.com

Propeller selection, General information – Yamaha F25 User Manual

Page 15

background image

General information

10

CAUTION:

ECM01050

All 4-stroke engines are shipped from the
factory without engine oil.

EMU25742

Propeller selection

The performance of your outboard motor will
be critically affected by your choice of propel-
ler, as an incorrect choice could adversely af-
fect performance and could also seriously
damage the motor. Engine speed depends on
the propeller size and boat load. If engine
speed is too high or too low for good engine
performance, this will have an adverse effect
on the engine.
Yamaha outboard motors are fitted with pro-
pellers chosen to perform well over a range of
applications, but there may be uses where a
propeller with a different pitch would be more
appropriate. For a greater operating load, a
smaller-pitch propeller is more suitable as it
enables the correct engine speed to be main-
tained. Conversely, a larger-pitch propeller is
more suitable for a smaller operating load.
Yamaha dealers stock a range of propellers,
and can advise you and install a propeller on
your outboard that is best suited to your appli-
cation.

NOTE:

Select a propeller which will allow the engine
to reach the middle or upper half of the oper-
ating range at full throttle with the maximum
boat load. If operating conditions such as light
boat loads then allow the engine r/min to rise
above the maximum recommended range, re-
duce the throttle setting to maintain the en-
gine in the proper operating range.

For instructions on propeller removal and in-
stallation, see page 40.

ZMU01710

1. Propeller diameter in inches

2. Propeller pitch in inches
3. Type of propeller (propeller mark)

ZMU04604

-

x

1

2 3

U69M15E0.book Page 10 Wednesday, April 5, 2006 4:48 PM