Yamaha F50 Manual

 
35 
Operation 
EMU26901 
Installation
CAUTION:
 
ECM00110  
Incorrect engine height or obstructions
to smooth water flow (such as the design
or condition of the boat, or accessories
such as transom ladders or depth finder
transducers) can create airborne water
spray while the boat is cruising. Severe
engine damage may result if the motor is
operated continuously in the presence of 
airborne water spray.
NOTE:
 
During water testing check the buoyancy of
the boat, at rest, with its maximum load.
Check...

 
Operation 
36 
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...

 
Operation 
37 
line fumes. 
 
Check fuel line connections to be sure they
are tight (if equipped Yamaha fuel tank or
boat tank). 
 
Be sure the fuel tank is positioned on a se-
cure, flat surface, and that the fuel line is
not twisted or flattened, or likely to contact
sharp objects (if equipped Yamaha fuel
tank or boat tank). 
 
Check the water in the fuel filter with the
water separator warning device. Place the
gear shift lever in neutral and turn the main
switch to “”(on). If the buzzer sounds...

 
Operation 
38 
1. Remove the fuel tank cap.
2. Carefully fill the fuel tank.
3. Securely close the cap after filling the
tank. Wipe up any spilled fuel. 
EMU27270 
Ring Free Fuel Additive 
Gasoline is a precise blend of many different
substances, each chosen to give certain
characteristics. Gasoline blends have been
changing in recent years in response to con-
cerns about pollution and resulting emis-
sions regulations. One of the most obvious
changes has been the elimination of lead
from most fuels....

 
Operation 
39 
2. If there is a fuel joint on the motor, firmly
connect the fuel line to the joint. Then
firmly connect the other end of the fuel
line to the joint on the fuel tank.
3. If a steering friction adjuster is provided
on your outboard motor, securely attach
the fuel line to the fuel line clamp.
NOTE:
 
During engine operation place the tank hori-
zontally, otherwise fuel cannot be drawn 
from the fuel tank.
4. Squeeze the primer pump with the outlet
end up until you feel it become firm....

 
Operation 
40 
to a secure place on your clothing, or
your arm or leg while operating. 
 
Do not attach the lanyard to clothing
that could tear loose. Do not route the
lanyard where it could become entan-
gled, preventing it from functioning. 
 
Avoid accidentally pulling the lanyard
during normal operation. Loss of en-
gine power means the loss of most
steering control. Also, without engine
power, the boat could slow rapidly. This
could cause people and objects in the 
boat to be thrown forward. 
3....

 
Operation 
41
NOTE:
 
The start-in-gear protection device prevents
the engine from starting except when in neu- 
tral.
2. Attach the engine stop switch lanyard to
a secure place on your clothing, or your
arm or leg. Then install the lock plate on
the other end of the lanyard into the en-
gine stop switch.
WARNING
 
EWM00120  
 
Attach the engine stop switch lanyard
to a secure place on your clothing, or
your arm or leg while operating. 
 
Do not attach the lanyard to clothing
that could tear loose....

 
Operation 
42 
again.
NOTE:
 
 
When the engine is cold, it needs to be
warmed up. For further information, see
page 42. 
 
If the engine is warm and fails to start,
open the throttle slightly and try to start the
engine again. If the engine still fails to 
start, see page 73. 
EMU27670 
Warming up engine 
EMU27710 
Manual start and electric start 
models 
1. After starting the engine, allow it to idle
for 3 minutes to warm up. Failure to do
so will shorten engine life.
2. Be sure the low oil...

 
Operation 
43 
2. Move the gear shift lever quickly and
firmly from neutral to forward.
Remote control models
1. Pull up the neutral interlock trigger (if
equipped) and move the remote control
lever quickly and firmly from neutral to
forward.
 
EMU27785 
Reverse (automatic reverse lock and 
power trim and tilt models)
WARNING
 
EWM00190  
When operating in reverse, go slowly. Do
not open the throttle more than half. Oth-
erwise the boat could become unstable,
which could result in loss of control and...

 
Operation 
44 
EMU30880 
Trolling 
EMU30890 
Adjusting trolling speed 
The trolling speed on outboard motors
equipped with the variable trolling RPM
switches can be adjusted approximately 50
r/min with each press of a switch.
To increase the trolling speed, press the “”
switch.
To decrease the trolling speed, press the
“” switch.
NOTE:
 
 
The trolling speed changes approximately
50 r/min each time a switch is pressed. 
 
If the trolling speed has been adjusted, the
engine returns to the normal...