Yamaha F2.5A Owner's Manual page 52

3-5
EMU01298
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 engine to overheat. If the mounting-
height is too low, the water-resistance will
increase and thereby reduce engine effi-
ciency. Mount the engine so that the anti-
cavitation plate is between the bottom of the
boat and a level 25 mm (1 in.) below it.
NOTE:
@
G
The optimum mounting height of the out-
board motor is affected by the boat/motor
combination and the desired use. Test
runs at different heights can help deter-
mine the optimum mounting height.
G Refer to the section "TRIMMING OUT-
BOARD MOTOR" for instructions on set-
ting the trim angle of the outboard.
GB