2000 YAMAHA YZ426F warning

5 - 46
CHAS
EC563000
REMOVAL POINTS
EC563202
Ring nut
1. Remove:
lRing nut 1
Use the ring nut wrench 2.
WARNING
Support the steering shaft so that it may
not fall down.
Ring nut wrench:
YU-33975/90890-01403
EC563300
Bearing (lower)
1. Remove:
lBearing (lower) 1
Use the floor chisel 2.
ACHTUNG:CAUTION:
Take care not to damage the steering shaft
thread.
EC563400
Ball race
1. Remove:
lBall race 1
Remove the ball race using long rod 2
and the hammer.
EC564000
INSPECTION
EC564200
Steering shaft
1. Inspect:
lSteering shaft 1
Bend/damage ® Replace.
STEERING

5 - 50
CHASSWINGARM
EC570000
SWINGARM
Extent of removal:1 Swingarm removal
Extent of removal Order Part name Q’ty Remarks
STEERING REMOVAL
Refer to “FRONT BRAKE AND REAR
BRAKE” section.
Shift the brake pedal backward. Preparation for removal Hold the machine by placing the
suitable stand under the engine.
Brake hose holder
Rear caliper
Bolt (brake pedal)
Drive chain
1 Chain support 1
2 Chain tensioner (lower) 1
3 Bolt (rear shock absorber-relay
arm)1 Hold the swingarm.
4 Bolt (connecting rod) 1
5 Pivot shaft 1
6 Swingarm 1
WARNING
Support the machine securely so there is nodanger of it falling over.
1

5 - 57
CHASREAR SHOCK ABSORBER
EC580000
REAR SHOCK ABSORBER
Extent of removal:1 Rear shock absorber removal2 Rear shock absorber disassembly
Extent of removal Order Part name Q’ty Remarks
Preparation for removalREAR SHOCK ABSORBER
REMOVAL
Hold the machine by placing the
suitable stand under the engine.
Seat and fitting band Refer to “SAET, FUEL TANK AND SIDE
COVERS” section.
Silencer Refer to “EXHAUST PIPE AND
SILENCER” section.
1 Bolt (reservoir tank) 1
2 Clamp (air cleaner joint) 1Only loosening.
3 Rear frame 1
4 Bolt (rear shock absorber-relay
arm)1 Hold the swingarm.
5 Bolt (rear shock absorber-frame) 1
6 Rear shock absorber 1
7 Locknut 1Only loosening.
8 Adjuster 1Only loosening.
9 Spring guide (lower) 1
WARNING
Support the machine securely so there is nodanger of it falling over.
1
2

5 - 59
CHAS
EC586000
HANDLING NOTE
WARNING
This shock absorber is provided with a
separate type tank filled with high-pressure
nitrogen gas. To prevent the danger of
explosion, read and understand the follow-
ing information before handling the shock
absorber.
The manufacturer can not be held respon-
sible for property damage or personal
injury that may result from improper han-
dling.
1. Never tamper or attempt to disassem-
ble the cylinder or the tank.
2. Never throw the shock absorber into
an open flame or other high heat. The
shock absorber may explode as a
result of nitrogen gas expansion and/
or damage to the hose.
3. Be careful not to damage any part of
the gas tank. A damaged gas tank will
impair the damping performance or
cause a malfunction.
4. Take care not to scratch the contact
surface of the piston rod with the cylin-
der; or oil could leak out.
5. Never attempt to remove the plug at
the bottom of the nitrogen gas tank. It
is very dangerous to remove the plug.
6. When scrapping the shock absorber,
follow the instructions on disposal.
EC587000
NOTES ON DISPOSAL (YAMAHA DEALERS
ONLY)
Before disposing the shock absorber, be sure
to extract the nitrogen gas from valve 1. Wear
eye protection to prevent eye damage from
escaping gas and/or metal chips.
WARNING
To dispose of a damaged or worn-out
shock absorber, take the unit to your
Yamaha dealer for this disposal procedure.
REAR SHOCK ABSORBER

7 - 1
TUN

EC700000
TUNING
EC710000
ENGINE
Carburetor setting
l
The air/fuel mixture will vary depending on
atmospheric conditions. Therefore, it is nec-
essary to take into consideration the air pres-
sure, ambient temperature, humidity, etc.,
when adjusting the carburetor.
l
Perform a test run to check for proper engine
performance (e.g., throttle response) and
spark plug(-s) discoloration or fouling. Use
these readings to determine the best possi-
ble carburetor setting.
NOTE:

It is recommended to keep a record of all car-
buretor settings and external conditions (e.g.,
atmospheric conditions, track/surface condi-
tions, lap times) to make future carburetor set-
ting easier.
WARNING

l
The carburetor is a part of the fuel line.
Therefore, be sure to install it in a well-
ventilated area, away from flammable
objects and any sources of fire.
l
Never look into the carburetor intake.
Flames may shoot out from the pipe if the
engine backfires while it is being started.
Gasoline may be discharged from the
accelerator pump nozzle when the carbu-
retor has been removed.
CAUTION:

l
The carburetor is extremely sensitive to
foreign matter (dirt, sand, water, etc.).
During installation, do not allow foreign
matter to get into the carburetor.
l
Always handle the carburetor and its com-
ponents carefully. Even slight scratches,
bends or damage to carburetor parts may
prevent the carburetor from functioning
correctly. Carefully perform all servicing
with the appropriate tools and without
applying excessive force.
l
When the engine is stopped or when
riding at no load, do not open and close
the throttle unnecessarily. Otherwise, too
much fuel may be discharged, starting
may become difficult or the engine may
not run well.
SETTING
7

7 - 13
TUNSETTING
EC727020
Spring preload adjustment
The spring preload is adjusted by installing the
adjustment washer 1 between the fork spring
2 and damper rod 3.
CAUTION:
Do not install three or more adjustment
washers for each front fork.
WARNING
Always adjust each front fork to the same
setting. Uneven adjustment can cause poor
handling and loss of stability.
Load
õFork stroke
1Without adjustment washer (standard)
21 adjustment washer
32 adjustment washers
Standard washer quantity:
Zero adjustment washers
Extent of adjustment:
Zero ~ 2 adjustment washers
EC72A001
Setting of spring after replacement
As the front fork setting can be easily affected
by rear suspension, take care so that the
machine front and rear are balanced (in posi-
tion, etc.) when setting the front fork.
1. Use of soft spring
Generally a soft spring gives a soft riding
feeling. Rebound damping tends to
become stronger and the front fork may
sink deeply over a series of gaps.
To set a soft spring:
lChange the rebound damping.
Turn out one or two clicks.
lChange the compression damping.
Turn in one or two clicks.