2006 YAMAHA YFZ450 engine

4-23
EBU00930
Fuel cock
The fuel cock supplies fuel from the fuel tank to
the carburetor.
The fuel cock has three positions.
OFF: With the lever in this position, fuel will
not flow. Always turn the lever to this posi-
tion when the engine is not running.
ON: With the lever in this position, fuel flows
to the carburetor. Normal riding is done
with the lever in this position.
RES: This indicates reserve. If you run out of
fuel while riding, turn the lever to this posi-
tion. THEN FILL THE FUEL TANK AT THE
FIRST OPPORTUNITY. After refuelling,
return the fuel cock lever to the “ON” posi-
tion.
5TG-9-62 4 5/12/05 5:18 PM Page 4-23

4-25
EBU00950
Starter (choke) “1”
Starting a cold engine requires a richer air-fuel
mixture. A separate starter circuit supplies this
mixture.
Move in direction ato turn on the starter
(choke).
Move in direction bto turn off the starter
(choke).
Refer to “Starting a cold engine” for proper oper-
ation. (See page 6-3.)
1. Starter (choke) “1”1. Starter (enrichisseur) “1”1. Starter (choke) “1”
5TG-9-62 4 5/12/05 5:18 PM Page 4-25

5-1
EBU01130
PRE-OPERATION CHECKS
Before using this machine, check the following points:
ITEM ROUTINE PAGE
Front brake9Check operation lever, free play, fluid level and fluid leakage. 5-7–5-11, 8-81,
9Fill with DOT 4 brake fluid if necessary. 8-85–8-91
Rear brake9Check operation, fluid level and fluid leakage. 5-7–5-11
9Fill with DOT 4 brake fluid if necessary. 8-83–8-89, 8-93
Clutch9Check operation, condition and lever free play. 8-103
Parking brake9Check operation, condition and cable length. 8-97–8-99
Fuel 9Check fuel level.
9Fill with fuel if necessary.5-13–5-15
Engine oil9Check oil level.
9Fill with oil if necessary.5-17, 8-25–8-41
Coolant reservoir 9Check coolant level in reservoir.
9Fill with coolant if necessary.5-19–5-21, 8-43–8-53
Drive chain9Check chain slack and condition.
9Adjust if necessary.5-21, 8-105–8-113
Throttle9Check for proper throttle cable operation and free play. 5-21, 8-79
Wheels and tires9Check tire pressure, wear and damage. 5-23–5-29, 8-125–8-127
Fittings and fasteners9Check all fittings and fasteners. 5-29
Lights and switches9Check for proper operation. 5-29, 8-99, 8-137–8-141
5TG-9-62 5-6 5/13/05 1:45 PM Page 5-1

5-13
EBU14571
Fuel
Make sure there is sufficient gasoline in the tank.
NOTE:
If knocking or pinging occurs, use a different
brand of gasoline or higher octane grade.
cC
Use only unleaded gasoline. The use of leaded
gasoline will cause severe damage to internal
engine parts, such as the valves and piston
rings, as well as to the exhaust system.
Recommended fuel:
PREMIUM UNLEADED GASOLINE
ONLY
For Europe:
PREMIUM UNLEADED GASOLINE
ONLY with a research octane number
of 97 or higher
Fuel tank capacity:
Total:
10.0 L
Reserve:
1.9 L
5TG-9-62 5-6 5/13/05 1:45 PM Page 5-13

5-15
w
8Do not overfill the fuel tank. Fuel expands
when it heats up. If the fuel tank is over-
filled, fuel could spill out due to heat from
the engine or the sun.
8Be careful not to spill fuel, especially on
the engine or exhaust pipe which can
cause a fire and severe injury. Wipe up
any spilled fuel immediately.
8Do not refuel right after the engine has
been running and is still very hot.
8Be sure the fuel tank cap is closed secure-
ly.q
w
1. Fuel tank filler tube 2. Fuel level1. Tube de remplissage du réservoir de carburant
2. Niveau de carburant
1. Tubo de llenado del depósito de combustible
2. Nivel de combustible
5TG-9-62 5-6 5/13/05 1:45 PM Page 5-15

5-17
EBU10842
Engine oil
Make sure the engine oil is at the specified level.
Add oil as necessary. (See page 8-25.)
cC
8In order to prevent clutch slippage (since
the engine oil also lubricates the clutch),
do not mix any chemical additives. Do not
use oils with a diesel specification of “CD”
or oils of a higher quality than specified. In
addition, do not use oils labeled “ENERGY
CONSERVING II” or higher.
8Make sure that no foreign material enters
the crankcase.
Recommended engine oil type and quantity:
See page 10-2.
5TG-9-62 5-6 5/13/05 1:45 PM Page 5-17

5-19
EBU13160
Coolant
Check the coolant level in the coolant reservoir
when the engine is cold. (The coolant level will
vary with engine temperature.) The coolant level
is satisfactory if it is between the minimum and
maximum level marks on the coolant reservoir. If
the coolant level is at or below the minimum
level mark, add distilled water to bring the level
up to the maximum level mark. Change the
coolant every two years. (See pages 8-43–8-53
for details.)
cC
Hard water or salt water is harmful to the
engine. You may use soft water if you cannot
get distilled water.
Coolant reservoir capacity
(up to the maximum level mark):
0.29 L
5TG-9-62 5-6 5/13/05 1:45 PM Page 5-19

5-21
w
Wait for the engine and radiator to cool
before removing the radiator cap. You could
be burned by hot fluid and steam blown out
under pressure. Always put a thick rag over
the cap when opening. Allow any remaining
pressure to escape before completely
removing the cap.
EBU04980
Chain
Check the general condition of the chain and
check the chain slack before every ride.
Lubricate and adjust the chain as necessary.
(See pages 8-105–8-113 for details.)
EBU10830
Throttle lever
Check to see that the throttle lever operates cor-
rectly. It must open smoothly and spring back to
the idle position when released. Have a Yamaha
dealer repair as necessary for proper operation.
5TG-9-62 5-6 5/13/05 1:45 PM Page 5-21