Installation
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.
EWM01590
WARNING
Overpowering a boat could cause se-
G
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-
G
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.
EMU33470
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-engine
boats, mount the outboard motor on the cen-
terline (keel line) of the boat.
1. Center line (keel line)
44
1
ZMU01760
EMU26931
Mounting height (boat bottom)
The mounting height of your outboard motor
affects its efficiency and reliability. If it is
mounted too high, propeller ventilation may
occur, which will reduce propulsion due to ex-
cessive propeller slip, and the water intakes
for the cooling system may not get adequate
water supply, which can cause engine over-
heating. If the engine is mounted too low, wa-
ter resistance (drag) will increase, thereby
reducing engine efficiency and performance.
Most commonly, outboard motor should be
mounted so that the anti-cavitation plate is in
alignment with the bottom of the boat. The op-
timum mounting height of the outboard motor
is affected by the boat/motor combination and
the desired use. Test runs at different heights
can help determine the optimum mounting
height. Consult your Yamaha dealer or boat
manufacturer for further information on deter-
mining the proper mounting height.
ECM01630
NOTICE
During water testing, check the buoyan-
G
cy of the boat, at rest, with its maximum
load. Check that the static water level on
the exhaust housing is low enough to
prevent water entry into the power head
when water rises due to waves when the
outboard is not running.
ZMU01762