Yamaha C40 Manual

 
General information 
6 
bend that may obstruct the view of other wa-
ter vessels, the operator should sound a pro-
longed blast on the whistle (4 to 6 seconds).
If another vessel is around the bend, it too
should sound the whistle. Even if no reply is
heard, however, the vessel should still pro-
ceed around the bend with caution. If you
navigate such waters with your boat, you will
need to carry a portable air horn, available
from local marine supply stores. 
Fishing vessel right-of-way 
All vessels...

 
General information 
7 
EMU25540 
Fueling instructions
WARNING
 
EWM00010  
GASOLINE AND ITS VAPORS ARE HIGH-
LY FLAMMABLE AND EXPLOSIVE! 
 
Do not smoke when refueling, and keepaway from sparks, flames, or other
sources of ignition. 
 
Stop engine before refueling. 
 
Refuel in a well-ventilated area. Refuel
portable fuel tanks off the boat. 
 
Take care not to spill gasoline. If gaso-
line spills, wipe it up immediately with
ZMU01708
✩✦✯✬✤✲✲✣ ✪ 	
 


 

 
General information 
8 
dry rags. 
 
Do not overfill the fuel tank. 
 
Tighten the filler cap securely after re-
fueling. 
 
If you should swallow some gasoline,
inhale a lot of gasoline vapor, or get
gasoline in your eyes, get immediate
medical attention. 
 
If any gasoline spills onto your skin, im-
mediately wash with soap and water.
Change clothing if gasoline spills on it. 
 
Touch the fuel nozzle to the filler open-
ing or funnel to help prevent electro- 
static sparks.
CAUTION:
 
ECM00010...

 
General information 
9 
speed is too high or too low for good engine
performance, this will have an adverse effect
on the engine.
Yamaha outboard motors are fitted with pro-
pellers chosen to perform well over a range
of applications, but there may be uses where
a propeller with a different pitch would be
more appropriate. For a greater operating
load, a smaller-pitch propeller is more suit-
able as it enables the correct engine speed
to be maintained. Conversely, a larger-pitch
propeller is more...

 
10 
Basic components 
EMU25796 
Main components
NOTE:
 
* May not be exactly as shown; also may not be included as standard equipment on all mod- 
els. 
40, 50 
EMU25802 
Fuel tank 
If your model was equipped with a portable
fuel tank, its function is as follows.
WARNING
 
EWM00020  
The fuel tank supplied with this engine is
its dedicated fuel reservoir and must not
be used as a fuel storage container. Com-
mercial users should conform to relevant
licensing or approval authority regula-
11
14 1512 13...

 
Basic components 
11 
tions. 
EMU25830 
Fuel joint 
This joint is used to connect the fuel line. 
EMU25841 
Fuel gauge 
This gauge is located on either the fuel tank
cap or on the fuel joint base. It shows the ap-
proximate amount of fuel remaining in the
tank. 
EMU25850 
Fuel tank cap 
This cap seals the fuel tank. When removed,
the tank can be filled with fuel. To remove the
cap, turn it counterclockwise. 
EMU25860 
Air vent screw 
This screw is on the fuel tank cap. To loosen
the screw, turn it...

 
Basic components 
12 
EMU26201 
Neutral interlock trigger 
To shift out of neutral, first pull the neutral in-
terlock trigger up. 
EMU26211 
Neutral throttle lever 
To open the throttle without shifting into ei-
ther forward or reverse, put the remote con-
trol lever in the neutral position and lift the
neutral throttle lever.
NOTE:
 
The neutral throttle lever will operate only
when the remote control lever is in neutral.
The remote control lever will operate only
when the neutral throttle lever is...

 
Basic components 
13 
EMU25941 
Throttle grip 
The throttle grip is on the tiller handle. Turn
the grip counterclockwise to increase speed
and clockwise to decrease speed. 
EMU25961 
Throttle indicator 
The fuel consumption curve on the throttle
indicator shows the relative amount of fuel
consumed for each throttle position. Choose
the setting that offers the best performance
and fuel economy for the desired operation. 
EMU25970 
Throttle friction adjuster 
A friction device provides adjustable resis-...

 
Basic components 
14 
When constant speed is desired, tighten the
adjuster to maintain the desired throttle set-
ting. 
EMU25990 
Engine stop lanyard switch 
The lock plate must be attached to the en-
gine stop switch for the engine to run. The
lanyard should be attached to a secure place
on the operator’s clothing, or arm or leg.
Should the operator fall overboard or leave
the helm, the lanyard will pull out the lock
plate, stopping ignition to the engine. This
will prevent the boat from running away...

 
Basic components 
15 
EMU26090 
Main switch 
The main switch controls the ignition system;
its operation is described below. 
 
“”  
(off) 
With the main switch in the “” (off) posi-
tion, the electrical circuits are off, and the key
can be removed. 
 
“”  
(on) 
With the main switch in the “” (on) posi-
tion, the electrical circuits are on, and the key
cannot be removed. 
 
“”  
(start) 
With the main switch in the “” (start) po-
sition, the starter motor turns to start the en-
gine. When the key...