Yamaha F8A Outboard Motor User Manual


 
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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:
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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.
Refer to the section TRIMMING OUT-
BOARD MOTOR for instructions on set-
ting the trim angle of the outboard.
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U68T13.book Page 3 Wednesday, August 8, 2001 12:37 PM