Yamaha F 40 User Guide

 
Maintenance 
65
NOTE:
 
If the propeller nut does not align with the
propeller shaft hole after tightening to the
specified torque, tighten the nut further to 
align it with the hole. 
EMU29282 
Changing 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...

 
Maintenance 
66 
level plug.
7. Put a new gasket on the gear oil drain
screw. Insert and tighten the gear oil
drain screw. 
EMU29302 
Cleaning fuel tank
WARNING
 
EWM00920  
Gasoline is highly flammable, and its va-
pors are flammable and explosive. 
 
If you have any question about properly
doing this procedure, consult your
Yamaha dealer. 
 
Keep away from sparks, cigarettes,
flames, or other sources of ignition
when cleaning the fuel tank. 
 
Remove the fuel tank from the boat be-
fore cleaning...

 
Maintenance 
67 
EMU29320 
Checking battery (for electric start 
models)
WARNING
 
EWM00330  
Battery electrolytic fluid is dangerous; it
contains sulfuric acid and therefore is
poisonous and highly caustic.
Always follow these preventive mea-
sures: 
 
Avoid bodily contact with electrolytic
fluid as it can cause severe burns or
permanent eye injury. 
 
Wear protective eye gear when han-
dling or working near batteries.
Antidote (EXTERNAL): 
 
SKIN - Flush with water. 
 
EYES - Flush with water for...

 
Maintenance 
68 
of charge. Installing a voltmeter will help
you monitor your battery. If you will not
use the boat for a month or more, re-
move the battery from the boat and store
it in a cool, dark place. Completely re-
charge the battery before using it.
3. If the battery will be stored for longer
than a month, check the specific gravity
of the fluid at least once a month and re-
charge the battery when it is low.
NOTE:
 
Consult a Yamaha dealer when charging or 
re-charging batteries. 
EMU29331...

 
Maintenance 
69 
marine growth.
Do not use anti-fouling paint which includes
copper or graphite. These paints can cause
more rapid engine corrosion.
ZMU01943 

 
70 
Trouble Recovery 
EMU29424 
Troubleshooting 
A problem in the fuel, compression, or igni-
tion systems can cause poor starting, loss of
power, or other problems. This section de-
scribes basic checks and possible remedies,
and covers 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
flashing, consult your Yamaha dealer. 
Starter will not operate. 
Q. Is...

 
Trouble Recovery 
71 
Q. Is fuel system obstructed?
A. Check for pinched or kinked fuel line or
other 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...

 
Trouble Recovery 
72 
A. Have serviced by a Yamaha dealer.
Q. Is load on boat improperly distributed?
A. Distribute load to place boat on an even
plane.
Q. Is water pump or thermostat faulty?
A. Have serviced by a Yamaha dealer.
Q. Is there excess water in fuel filter cup?
A. Drain filter cup. 
Engine power loss. 
Q. Is propeller damaged?
A. Have propeller repaired or replaced.
Q. Is propeller pitch or diameter incorrect?
A. Install correct propeller to operate out-
board at its recommended speed...

 
Trouble Recovery 
73 
Q. Is fuel joint connection incorrect?
A. Connect correctly.
Q. Is heat range of spark plug incorrect?
A. Inspect spark plug and replace it with rec-
ommended type.
Q. Is high pressure fuel pump drive belt bro-
ken?
A. Have serviced by a Yamaha dealer.
Q. Is engine not responding properly to shift
lever position?
A. Have serviced by a Yamaha dealer. 
Engine vibrates excessively. 
Q. Is propeller damaged?
A. Have propeller repaired or replaced.
Q. Is propeller shaft damaged?
A....

 
Trouble Recovery 
74 
EMU29511 
Power trim and tilt / power tilt will not 
operate 
If the engine cannot be tilted up or down with
the power trim and tilt / the power tilt because
of a discharged battery or a failure with the
power trim and tilt unit / the power tilt unit, the
engine can be tilted manually.
1. Loosen the manual valve screw by turn-
ing it clockwise until it stops.2. Put the engine in the desired position,
then tighten the manual valve screw by
turning it counterclockwise. 
EMU29532...