Yamaha T50D - Manual (Page 31)

Operation
26
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 in alignment with the bottom of the
boat.
NOTE:
● 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. Con-
sult your Yamaha dealer or boat
manufacturer for further information on de-
termining the proper mounting height.
● For instructions on setting the trim angle of
the outboard motor, see page 32.
EMU30172
Breaking in engine
Your new engine requires a period of break-
in to allow mating surfaces of moving parts to
wear in evenly. Correct break-in will help en-
sure proper performance and longer engine
life.
CAUTION:
ECM00800
Failure to follow the break-in procedure
could result in reduced engine life or
even severe engine damage.
EMU27080
Procedure for 4-stroke models
Run the engine under load (in gear with a
propeller installed) as follows.
1.
For the first hour of operation:
Run the engine at 2000 r/min or at ap-
proximately half throttle.
2. For the second hour of operation:
Run the engine at 3000 r/min or at ap-
proximately three-quarter throttle.
3. For the next eight hours of operation:
Avoid continuous operation at full throt-
tle for more than five minutes at a time.
4. After the first 10 hours:
Operate the engine normally.
EMU27101
Preoperation checks
WARNING
EWM00080
If any item in the preoperation check is
not working properly, have it inspected
and repaired before operating the out-
board motor. Otherwise an accident
could occur.
CAUTION:
ECM00120
Do not start the engine out of water. Over-
heating and serious engine damage can
occur.
EMU27110
Fuel
● Check to be sure you have plenty of fuel
for your trip.
● Make sure there are no fuel leaks or gaso-
line fumes.
ZMU01762