Yamaha 9.9 15 Outboard Motor User Manual


 
Installation
23
EMU26902
Installation
The information presented in this section is in-
tended as reference only. It is not possible to
provide complete instructions for every possi-
ble boat and motor combination. Proper
mounting depends in part on experience and
the specific boat and motor combination.
WARNING
EWM01590
Overpowering a boat could cause se-
vere instability. Do not install an out-
board motor with more horsepower than
the maximum rating on the capacity
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 conditions
such as poor handling, loss of control,
or fire hazards. For permanently mount-
ed models, your dealer or other person
experienced in proper rigging should
mount the motor.
EMU26911
Mounting the outboard motor
WARNING
EWM01720
Your dealer or other person experienced
in proper outboard motor mounting
should show you how to mount your out-
board motor.
The outboard motor should be mounted so
that the boat is well balanced. Otherwise, the
boat could be hard to steer. For single-engine
boats, mount the outboard motor on the cen-
terline (keel line) of the boat.
EMU26923
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.
1. Center line (keel line)
ZMU01760
1
ZMU02011
0–25mm
(0–1in)
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