Yamaha F150 Four Stroke Manual

Maintenance
54
7. Dispose of used oil according to local
regulations.
NOTE:

For more information on the disposal of
used oil, consult your Yamaha dealer.

Change the oil more often when operating
the engine under adverse conditions such
as extended trolling.
EMU29112Checking wiring and connectors

Check that each grounding wire is properly
secured.

Check that each connector is engaged se-
curely.
EMU29120Exhaust leakage
Start the engine and check that no exhaust
leaks from the joints between the...

Maintenance
55
5. Check that the tilt rod and trim rods are
free of corrosion or other flaws.
6. Activate the tilt-down switch until the trim
rods have retracted completely into the
cylinders.
7. Activate the trim-up switch until the tilt rod
is fully extended. Unlock the tilt support
lever.
8. Tilt the outboard motor down. Check that
the tilt rod and trim rods operate smooth-
ly.
NOTE:
Consult your Yamaha dealer if any operation
is abnormal.
EMU29171Checking propeller
WARNING
EWM00321
You could be...

Maintenance
56

Check the propeller shaft oil seal for dam-
age.
NOTE:
If the shear pin equipped: it is designed to
break if the propeller hits a hard underwater
obstacle to help protect the propeller and
drive mechanism. The propeller will then spin
freely on the shaft. If this happens, the shear
pin must be replaced.
EMU30660Removing the propellerEMU29194Spline models
1. Straighten the cotter pin and pull it out us-
ing a pair of pliers.
2. Remove the propeller nut, washer, and
spacer (if equipped).3....

Maintenance
57
NOTE:
If the propeller nut does not align with the pro-
peller shaft hole after tightening to the speci-
fied torque, tighten the nut further to align it
with the hole.
EMU29281Changing gear oil
WARNING
EWM00800

Be sure the outboard motor is securely
fastened to the transom or a stable
stand. You could be severely injured if
the outboard motor falls on you.

Never get under the lower unit while it is
tilted, even when the tilt support lever or
knob is locked. Severe injury could oc-
cur...

Maintenance
58
6. When the oil begins to flow out of the oil
level plug hole, insert and tighten the oil
level plug.
7. Insert and tighten the gear oil drain
screw.
EMU29312Inspecting and replacing anode(s)
Yamaha outboard motors are protected from
corrosion by sacrificial anodes. Inspect the
external anodes periodically. Remove scales
from the surfaces of the anodes. Consult a
Yamaha dealer for replacement of external
anodes.
CAUTION:
ECM00720
Do not paint anodes, as this would render
them ineffective....

Maintenance
59

Drink large quantities of water or milk
followed by milk of magnesia, beaten
egg, or vegetable oil. Get immediate
medical attention.
Batteries also generate explosive hydro-
gen gas; therefore, you should always fol-
low these preventive measures:

Charge batteries in a well-ventilated ar-
ea.

Keep batteries away from fire, sparks, or
open flames (for example: welding
equipment, lighted cigarettes, and so
on.)

DO NOT SMOKE when charging or han-
dling batteries.
KEEP BATTERIES AND...

Maintenance
60
Connect the RED battery cable to the POSI-
TIVE (+) terminal first. Then connect the
BLACK battery cable to the NEGATIVE (-) ter-
minal.
Connecting an accessory battery (optional)
1. Remove the accessory battery coupler
cover from the outboard motor.
2. Connect the accessory battery coupler to
the coupler of the accessory battery ca-
ble (optional). Use a connecting cable be-
tween the (-) terminals of the starting
battery and accessory battery. See the il-
lustrations of the wiring...

Maintenance
61
EMU29400Coating the boat bottom
A clean hull improves boat performance. The
boat bottom should be kept as clean of marine
growth as possible. If necessary, the boat bot-
tom can be coated with an anti-fouling paint
approved for your area to inhibit marine
growth.
Do not use anti-fouling paint which includes
copper or graphite. These paints can cause
more rapid engine corrosion.
U63P14E0.book  Page 61  Monday, June 6, 2005  4:57 PM 

Trouble Recovery
62
EMU29424
Troubleshooting
A problem in the fuel, compression, or ignition
systems can cause poor starting, loss of pow-
er, or other problems. This section describes
basic checks and possible remedies, and cov-
ers all Yamaha outboard motors. Therefore
some items may not apply to your model.
If your outboard motor requires repair, bring it
to your Yamaha dealer.
If the engine trouble warning indicator is flash-
ing, consult your Yamaha dealer.
Starter will not operate.
Q. Is battery...

Trouble Recovery
63
A. Check for pinched or kinked fuel line or oth-
er obstructions in fuel system.
Q. Is fuel contaminated or stale?
A. Fill tank with clean, fresh fuel.
Q. Is fuel filter clogged?
A. Clean or replace filter.
Q. Have ignition parts failed?
A. Have serviced by a Yamaha dealer.
Q. Has warning system activated?
A. Find and correct cause of warning.
Q. Is spark plug gap incorrect?
A. Inspect and adjust as specified.
Q. Is ignition wiring damaged or poorly con-
nected?
A. Check wires for...