2008 YAMAHA YFZ450 stop start

8-29
1
2
3
4
5
6
78
9
10
11

7. Start the engine and rev it up approximately
twenty times while momentarily creating ex-
haust system back pressure by blocking the
end of the muffler with a shop towel.
8. Stop the engine and allow the exhaust pipe to
cool.
9. Install the purging bolt and tighten it to the
specified torque.
WARNING

EWB02380
Never run the engine in an enclosed area when
purging the spark arrester, otherwise it could
cause injury to the eyes, burns, carbon monox-
ide poisoning, possibly leading to death, and
start a fire.

Always let the exhaust system cool prior to
touching exhaust components.

Always wear eye protection, and make sure
no one is behind the ATV.

Make sure there are no combustible materi-
als in the area.
EBU23940
Adjusting the carburetor
The carburetor should be checked and, if neces-
sary, adjusted at the intervals specified in the peri-
odic maintenance and lubrication chart. The
carburetor is an important part of the engine and
requires very sophisticated adjustment. Therefore,
most carburetor adjustments should be left to a
Yamaha dealer, who has the necessary profes-
sional knowledge and experience. The adjustment
described in the following section, however, may
be performed by the owner as part of routine main-
1. Purging bolt
2. Gasket
Tightening torque:
Purging bolt:
27 Nm (2.7 m·kgf, 20 ft·lbf)
1 2

9-1
1
2
3
4
5
6
7
89
10
11

EBU25860
CLEANING AND STORAGE
EBU25900
Cleaning
Frequent, thorough cleaning of your ATV will not
only enhance its appearance but will improve its
general performance and extend the useful life of
many components.
1. Before cleaning the ATV:
a. Block off the end of the exhaust pipe to
prevent water entry. A plastic bag and
strong rubber band may be used.
b. Make sure the spark plug and all filler caps
are properly installed.
2. If the engine case is excessively greasy, apply
degreaser with a paint brush. Do not apply de-
greaser to the chain, sprockets or wheel ax-
les.
3. Rinse the dirt and degreaser off with a garden
hose. Use only enough pressure to do the job.
CAUTION:

ECB00710
Excessive water pressure may cause water
seepage and deterioration of wheel bearings,
brakes, transmission seals and electrical de-
vices. Many expensive repair bills have result-ed from improper high-pressure detergent
applications such as those available in coin-
operated car washers.
4. Once most of the dirt has been hosed off,
wash all surfaces with warm water and mild,
detergent-type soap. An old toothbrush or bot-
tle brush is handy for hard-to-reach places.
5. Rinse the ATV off immediately with clean wa-
ter and dry all surfaces with a chamois, clean
towel or soft absorbing cloth.
6. Dry the chain and lubricate it to prevent it from
rusting.
7. Clean the seat with a vinyl upholstery cleaner
to keep the cover pliable and glossy.
8. Automotive type wax may be applied to all
painted and chrome plated surfaces. Avoid
combination cleaner-waxes. Many contain
abrasives which may mar the paint or protec-
tive finish. When finished cleaning, start the
engine and let it idle for several minutes.WARNING
EWB02310
Wet brakes may have reduced stopping ability,

INDEX
A
Accessories and loading ................................................ 6-6
Air filter element, cleaning ............................................ 8-24
B
Battery .......................................................................... 8-45
Brake and clutch levers, checking and lubricating ....... 8-42
Brake and shift pedals, checking and lubricating ......... 8-43
Brake fluid, changing.................................................... 8-35
Brake fluid level, checking............................................ 8-32
Brake lever ..................................................................... 4-5
Brake lever free play, checking the front ...................... 8-36
Brake light switches ..................................................... 8-39
Brake pads, checking the front and rear ...................... 8-31
Brake pedal .................................................................... 4-5
Brake pedal position, checking .................................... 8-36
Brakes, front and rear .................................................... 5-4
C
Cables, checking and lubricating ................................. 8-41
Carburetor, adjusting.................................................... 8-29
Chassis fasteners........................................................... 5-8
Cleaning ......................................................................... 9-1
Clutch lever .................................................................... 4-5
Clutch lever free play, adjusting ................................... 8-39
Coolant ................................................................. 5-4
,
8-20
Coolant temperature warning light ................................. 4-1
D
Drive chain ..................................................................... 5-5
Drive chain, lubricating ................................................. 8-41
E
Engine break-in .............................................................. 6-5
Engine, cold start ........................................................... 6-1
Engine idling speed ...................................................... 8-30
Engine oil ....................................................................... 5-4
Engine oil and oil filter element .................................... 8-14
Engine, starting a warm ................................................. 6-3
Engine stop switch ......................................................... 4-2
F
Fuel ........................................................................ 4-8
,
5-4
Fuel cock ........................................................................ 4-9
Fuel tank cap.................................................................. 4-7
Fuse, replacing............................................................. 8-46
H
Handlebar switches ........................................................ 4-2
Headlight beam, adjusting............................................ 8-49
Headlight bulb, replacing.............................................. 8-47
I
Identification numbers .................................................. 11-1
Indicator light and warning light...................................... 4-1
Instruments, lights and switches .................................... 5-8
K
Key identification number ............................................. 11-1