Clamping The Outboard Motor - Yamaha F2.5 Owner's Manual

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.
F2.5
1. Idle hole
2. Anti-cavitation plate
F4, F6
0-25 mm
(0-1 in)
1. Idle hole
2. Anti-cavitation plate
ECM02170
NOTICE
Check that the idle hole stays high
●
enough to keep out water getting inside
engine even if the boat is in stationary
with maximum load.
1
0–25mm
(0–1in)
2
ZMU07370
1
2
ZMU06796
Incorrect engine height or obstructions
●
to the smooth flow of water (such as the
design or condition of the boat) can cre-
ate airborne water spray while the boat
is cruising. If the motor is operated con-
tinuously in the presence of airborne
water spray, enough water could enter
the engine through the intake opening
on the top cowling to cause severe en-
gine damage. Eliminate the cause of the
airborne water spray.
TIP:
The optimum mounting height of the out-
●
board motor is affected by the boat and mo-
tor 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 determining the prop-
er mounting height.
For instructions on setting the trim angle of
●
the outboard motor, see page 62.
EMU39752

Clamping the outboard motor

1. Place the outboard motor on the transom
so that it is positioned as close to the cen-
ter as possible. Tighten the clamp screws
evenly and securely. Occasionally check
the clamp screws for tightness during op-
eration of the outboard motor because
they could become loose due to engine
vibration. WARNING! Loose clamp
screws could allow the outboard mo-
tor to fall off or move on the transom.
This could cause loss of control and
serious injury. Make sure the clamp
screws are tightened securely. Occa-
sionally check the screws for tight-
ness during operation.
Installation
[EWM00642]
41