CHASSIS
10-1
EAM20119
CHASSIS
EAM30168
SELECTION OF THE SECONDARY
REDUCTION RATIO (SPROCKET)
<Requirement for selection of secondary gear
reduction ratio>
•
It is generally said that the secondary gear ratio
should be reduced for a longer straight portion
of a speed course and should be increased for
a course with many corners. Actually, howev-
er, as the speed depends on the ground condi-
tion of the day of the race, be sure to run
through the circuit to set the machine suitable
for the entire course.
•
In actuality, it is very difficult to achieve settings
suitable for the entire course and some set-
tings may be sacrificed. Thus, the settings
should be matched to the portion of the course
that has the greatest effect on the race result.
In such a case, run through the entire course
while making notes of lap times to find the best
balance; then, determine the secondary reduc-
tion ratio.
•
If a course has a long straight portion where a
machine can run at maximum speed, the ma-
chine is generally set such that it can develop
its maximum revolutions toward the end of the
straight line, with care taken to avoid the en-
gine over-revving.
TIP
Riding technique varies from rider to rider and
the performance of a machine also vary from
machine to machine. Therefore, do not imitate
other rider’s settings from the beginning but
choose your own setting according to the level of
your riding technique.
EAM30169
DRIVE AND REAR WHEEL SPROCKETS
SETTING PARTS
EAM30170
TIRE PRESSURE
Tire pressure should be adjusted to suit the road
surface condition of the circuit.
•
Under a rainy, a muddy, a sandy, or a slippery
condition, the tire pressure should be lower for
a larger area of contact with the road surface.
•
Under a stony or a hard road condition, the tire
pressure should be higher to prevent a flat tire.
Secondary reduction ratio = Number of
rear wheel sprocket teeth/Number of
drive sprocket teeth
Secondary reduction ratio
3.923 (51/13)
Part name
Type
Part number
Drive
sprocket “1”
(STD)
13T
9383B-13218
Rear wheel
sprocket “2”
47T
17D-25447-50
48T
17D-25448-50
49T
B2W-25449-00
50T
B2W-25450-00
(STD)
51T
B2W-25451-00
52T
17D-25452-50
Standard tire pressure
100 kPa (1.00 kgf/cm², 15 psi)
Extent of adjustment
60–80 kPa (0.60–0.80 kgf/cm², 9–
12 psi)
Extent of adjustment
100–120 kPa (1.00–1.20 kgf/cm²,
15–18 psi)
Part name
Type
Part number
Summary of Contents for YZ 2023 Series
Page 6: ...EAM20162 YAMAHA MOTOR CORPORATION U S A YZ MOTORCYCLE LIMITED WARRANTY...
Page 10: ......
Page 44: ...MOTORCYCLE CARE AND STORAGE 1 32...
Page 61: ...TIGHTENING TORQUES 2 16...
Page 62: ...CABLE ROUTING DIAGRAM 2 17 EAM20152 CABLE ROUTING DIAGRAM Frame and engine left side view...
Page 64: ...CABLE ROUTING DIAGRAM 2 19 Frame and engine right side view...
Page 66: ...CABLE ROUTING DIAGRAM 2 21 Handlebar front view...
Page 68: ...CABLE ROUTING DIAGRAM 2 23 Frame and engine top view...
Page 70: ...CABLE ROUTING DIAGRAM 2 25 Frame and battery top view...
Page 72: ...CABLE ROUTING DIAGRAM 2 27 Rear brake right side view...
Page 74: ...CABLE ROUTING DIAGRAM 2 29...
Page 112: ...ELECTRICAL SYSTEM 3 36...
Page 148: ...REAR BRAKE 4 34 system Refer to BLEEDING THE HYDRAULIC BRAKE SYSTEM on page 3 25...
Page 154: ...HANDLEBAR 4 40 Throttle grip free play 3 0 6 0 mm 0 12 0 24 in...
Page 187: ...INSTALLING THE TRANSMISSION 5 74...
Page 190: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 5 3 1 Oil filter element 2 Oil pump...
Page 191: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 5 4 1 Intake camshaft 2 Exhaust camshaft...
Page 264: ...TRANSMISSION 5 77...
Page 274: ...WATER PUMP 6 9...
Page 284: ...THROTTLE BODY 7 9...
Page 287: ......
Page 288: ...IGNITION SYSTEM 8 1 EAM20142 IGNITION SYSTEM EAM30277 CIRCUIT DIAGRAM...
Page 292: ...ELECTRIC STARTING SYSTEM 8 5 EAM20143 ELECTRIC STARTING SYSTEM EAM30279 CIRCUIT DIAGRAM...
Page 296: ...CHARGING SYSTEM 8 9 EAM20144 CHARGING SYSTEM EAM30282 CIRCUIT DIAGRAM...
Page 299: ...CHARGING SYSTEM 8 12...
Page 300: ...SIGNALING SYSTEM 8 13 EAM20154 SIGNALING SYSTEM EAM30348 CIRCUIT DIAGRAM...
Page 304: ...FUEL INJECTION SYSTEM 8 17 EAM20145 FUEL INJECTION SYSTEM EAM30284 CIRCUIT DIAGRAM...
Page 329: ...FUEL INJECTION SYSTEM 8 42...
Page 330: ...FUEL PUMP SYSTEM 8 43 EAM20146 FUEL PUMP SYSTEM EAM30287 CIRCUIT DIAGRAM...
Page 362: ...SELF DIAGNOSTIC FUNCTION AND DIAGNOSTIC CODE TABLE 9 15...
Page 372: ...CHASSIS 10 9...
Page 374: ......
Page 376: ......
Page 377: ...YZ250FXP 2023 WIRING DIAGRAM BAJ 2819U 13_WD indd 1 2022 04 01 9 58 37...
Page 378: ...YZ250FXP 2023 WIRING DIAGRAM BAJ 2819U 13_WD indd 2 2022 04 01 9 58 37...