ENGINE SPECIFICATIONS
2-4
Drivetrain
Primary reduction ratio
3.353 (57/17)
Transmission type
Constant mesh 6-speed
Gear ratio
1st
2.385
(31/13)
2nd
1.813
(29/16)
3rd
1.444
(26/18)
4th
1.143
(24/21)
5th
0.957
(22/23)
6th
0.815
(22/27)
Main axle runout limit
0.08 mm (0.0032 in)
Drive axle runout limit
0.08 mm (0.0032 in)
Secondary reduction ratio
3.923 (51/13)
Final
drive
Chain
Air filter
Air filter element
Wet element
Air filter oil grade
Yamaha foam air filter oil or other quality foam
air filter oil
Fuel pump
Pump
type
Electrical
Maximum consumption amperage
2.4 A
Fuel injector
Resistance
12.0
Throttle body
ID
mark
B7B1
Idling condition
Engine idling speed
1900–2100 r/min
Coolant
temperature
70–80
C (158–176
F)
Fuel line pressure (at idle)
300–390 kPa (3.0–3.9 kgf/cm², 43.5–56.6 psi)
Throttle grip free play
3.0–6.0 mm (0.12–0.24 in)
Summary of Contents for YZ250FX 2021
Page 6: ...EAM20162 YAMAHA MOTOR CORPORATION U S A YZ MOTORCYCLE LIMITED WARRANTY ...
Page 10: ......
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 153: ...HANDLEBAR 4 39 Throttle grip free play 3 0 6 0 mm 0 12 0 24 in ...
Page 166: ...FRONT FORK 4 52 1 ...
Page 184: ...CHAIN DRIVE 4 70 ...
Page 189: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 5 3 1 Oil filter element 2 Oil pump ...
Page 190: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 5 4 1 Intake camshaft 2 Exhaust camshaft ...
Page 264: ...TRANSMISSION 5 78 ...
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: ...YZ250FXM 2021 WIRING DIAGRAM BAJ 2819U 11_WD indd 1 2020 06 29 15 46 05 ...
Page 378: ...YZ250FXM 2021 WIRING DIAGRAM BAJ 2819U 11_WD indd 2 2020 06 29 15 46 06 ...