THROTTLE BODY
7-8
b. Remove the fuel tank bolt and lift the fuel
tank.
c. Disconnect the fuel hose from the fuel
pump.
Refer to “REMOVING THE FUEL TANK”
on page 7-2.
WARNING
EWA19380
Cover the fuel hose connection with a cloth
when disconnecting it. This is because re-
sidual pressure in the fuel hose could cause
fuel to spurt out when the hose is removed.
NOTICE
ECA24750
Make sure that the fuel hose is disconnected
by hand. Do not forcibly disconnect the hose
with tools.
d. Connect the pressure gauge “1” and the
fuel pressure adapter “2” to the fuel hose.
e. Start the engine.
f. Measure the fuel line pressure.
Out of specification
Replace the fuel
pump.
EAM30273
ADJUSTING THE THROTTLE POSITION
SENSOR
WARNING
EWA15950
• Handle the throttle position sensor with
special care.
• Never subject the throttle position sensor
to strong shocks. If the throttle position
sensor is dropped, replace it.
1. Check:
•
Throttle position sensor
Refer to “CHECKING THE THROTTLE PO-
SITION SENSOR INPUT VOLTAGE” on
page 8-57.
2. Adjust:
•
Throttle position sensor angle
a. Connect the Yamaha diagnostic tool.
Refer to “YAMAHA DIAGNOSTIC TOOL”
on page 8-21.
b. Temporary tighten the throttle position
sensor.
c. Check that the throttle grip is fully closed.
d. Connect the throttle position sensor to the
wire harness.
e. Set the Yamaha diagnostic tool to “diag-
nostic mode”.
f. Choose the diagnostic code No. “01”.
g. Adjust the throttle position sensor mount-
ed angle until “11”–“14” appears on the
Yamaha diagnostic tool.
h. After adjusting the throttle position sensor
mounted angle, tighten the throttle posi-
tion sensor screw “1”.
Pressure gauge
90890-03153
Pressure gauge
YU-03153
Fuel pressure adapter
90890-03186
Fuel pressure adapter
YM-03186
Fuel line pressure (at idle)
300–390 kPa (3.0–3.9 kgf/cm²,
43.5–56.6 psi)
1
2
1
2
Yamaha diagnostic tool USB (US)
90890-03269
Yamaha diagnostic tool (A/I)
90890-03264
FI diagnostic tool sub–lead
90890-03212
FI diagnostic tool sub–lead
YU-03212
OBD/ GST Leadwire kit
90890-03249
Throttle position sensor screw
3.5 N·m (0.35 kgf·m, 2.6 lb·ft)
T
R
.
.
1
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 ...