Installation; Mounting The Outboard Motor - Yamaha 40X Owner's Manual

Installation

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Installation
The information presented in this section is
intended as reference only. It is not possible
to provide complete instructions for every
possible boat and motor combination. Proper
mounting depends in part on experience and
the specific boat and motor combination.
EWM01590
WARNING
Overpowering a boat could cause se-
●
vere instability. Do not install an out-
board motor with more horsepower
than the maximum rating on the capac-
ity plate of the boat. If the boat does not
have a capacity plate, consult the boat
manufacturer.
Improper mounting of the outboard mo-
●
tor could result in hazardous condi-
tions such as poor handling, loss of
control, or fire hazards. For permanent-
ly mounted models, your dealer or oth-
er person experienced in proper rigging
should mount the motor.
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Mounting the outboard motor

The outboard motor should be mounted so
that the boat is well balanced. Otherwise, the
boat could be hard to steer. For single-en-
gine boats, mount the outboard motor on the
centerline (keel line) of the boat.
26
1. Center line (keel line)
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Mounting height
To run your boat at optimum efficiency, the
water resistance (drag) of the boat and out-
board motor must be made as little as possi-
ble. The mounting height of the outboard
motor greatly affects the water resistance. If
the mounting height is too high, cavitation
tends to occur, thus reducing the propulsion;
and if the propeller tips cut the air, the engine
speed will rise abnormally and cause the en-
gine to overheat. If the mounting height is too
low, the water resistance will increase and
thereby reduce engine efficiency. Mount the
outboard motor so that the anti-cavitation
plate is between the bottom of the boat and
a level 25 mm (1 in) below it.
0–25mm
(0–1in)
1
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