ELECTRICAL COMPONENTS
8-87
EAS28240
CHECKING THE SPEED SENSOR
1. Check:
• Speed sensor output voltage
Out of specification
→
Replace.
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a. Connect the pocket tester (DC 20 V) to the
speed sensor coupler (wire harness end) as
shown.
b. Set the main switch to “ON”.
c. Elevate the front wheel and slowly rotate it.
d. Measure the voltage of gray and gray/black.
With each full rotation of the front wheel, the
voltage reading should cycle from 0.6 V to 4.8
V to 0.6 V to 4.8 V.
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EAS28250
CHECKING THE RADIATOR FAN MOTOR
1. Check:
• Radiator fan motor
Faulty/rough movement
→
Replace.
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a. Disconnect the radiator fan motor coupler
from the wire harness.
b. Connect the battery (DC 12 V) as shown.
c. Measure the radiator fan motor movement.
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EAS28260
CHECKING THE COOLANT TEMPERATURE
SENSOR
1. Remove:
• Coolant temperature sensor
Refer to “CYLINDER HEAD (YP125R)” on
page 5-7 and “CYLINDER HEAD (YP250R)”
on page 5-67.
WARNING
EWA14130
• Handle the coolant temperature sensor
with special care.
• Never subject the coolant temperature sen-
sor to strong shocks. If the coolant temper-
ature sensor is dropped, replace it.
2. Check:
• Coolant temperature sensor resistance
Out of specification
→
Replace.
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a. Connect the pocket tester (
Ω
×
1k/
×
100) to
the coolant temperature sensor terminals as
shown.
b. Immerse the coolant temperature sensor “1”
in a container filled with coolant “2”.
TIP
Make sure the coolant temperature sensor ter-
minals do not get wet.
c. Place a thermometer “3” in the coolant.
Output voltage reading cycle
0.6 V to 4.8 V to 0.6 V to 4.8 V
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
• Positive tester probe
→
gray “1”
• Negative tester probe
→
gray/black “2”
• Positive tester probe
→
red “1”
• Negative tester probe
→
black “2”
Gy
P
B
/
W
O
/
R
Gy
/
B
Gy
/
R
1
2
Coolant temperature sensor re-
sistance
2.32–2.59 k
Ω
at 20 °C (68 °F)
310–326
Ω
at 80 °C (176 °F)
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
Summary of Contents for YP125R
Page 1: ...SERVICE MANUAL 2010 37P F8197 E0 YP125R YP250R...
Page 6: ......
Page 8: ......
Page 28: ...SPECIAL TOOLS 1 19...
Page 30: ...COOLING SYSTEM DIAGRAMS YP250R 2 73 CABLE ROUTING YP250R 2 75...
Page 31: ......
Page 55: ...LUBRICATION POINTS AND LUBRICANT TYPES YP125R 2 24...
Page 62: ...CABLE ROUTING YP125R 2 31 Front fork front view A 1 1 1 1 2 2 2 3 4 5 6 7...
Page 66: ...CABLE ROUTING YP125R 2 35 Engine right side view A 7 3 2 2 2 1 3 4 5 6 7...
Page 70: ...CABLE ROUTING YP125R 2 39 Engine left side view 2 1 3 4 A 3...
Page 72: ...CABLE ROUTING YP125R 2 41 Handlebar top view A 1 2 3 4 4 5 6 7 8 9 10 11 12 13 14 15 16 17...
Page 76: ...CABLE ROUTING YP125R 2 45 Tail brake light top view 2 1 3 4 B A 1 5 6...
Page 103: ...LUBRICATION POINTS AND LUBRICANT TYPES YP250R 2 72...
Page 108: ...CABLE ROUTING YP250R 2 77 Front fork front view 1 1 2 3 4 5 6 7 1 2 A 1 2...
Page 112: ...CABLE ROUTING YP250R 2 81 Engine right side view A 7 3 2 2 2 1 3 4 5 6 7 8 B...
Page 116: ...CABLE ROUTING YP250R 2 85 Engine left side view 2 1 3 4 5 6 B A 3 7...
Page 118: ...CABLE ROUTING YP250R 2 87 Handlebar top view A 1 2 3 4 4 5 6 7 8 8 9 10 11 12 13 14 15 16 17...
Page 122: ...CABLE ROUTING YP250R 2 91 Tail brake light top view 2 1 3 4 B A 1 5 6 8 7...
Page 124: ...CABLE ROUTING YP250R 2 93...
Page 127: ......
Page 172: ...ELECTRICAL SYSTEM 3 45...
Page 175: ......
Page 240: ...REAR SHOCK ABSORBER ASSEMBLIES AND SWINGARM 4 65...
Page 245: ......
Page 305: ...CRANKSHAFT YP125R 5 60 a 1...
Page 366: ...CRANKSHAFT YP250R 5 121...
Page 394: ...THROTTLE BODY 7 11...
Page 397: ......
Page 411: ...CHARGING SYSTEM 8 14...
Page 423: ...SIGNALING SYSTEM 8 26...
Page 427: ...COOLING SYSTEM 8 30...
Page 453: ...FUEL INJECTION SYSTEM 8 56...
Page 457: ...FUEL PUMP SYSTEM 8 60...
Page 466: ...IMMOBILIZER SYSTEM 8 69 a Light on b Light off...
Page 467: ...IMMOBILIZER SYSTEM 8 70...
Page 495: ......
Page 496: ...YAMAHA MOTOR ESPA A S A...