2010 YAMAHA YZ125LC charging

2-7
TIGHTENING TORQUES
ELECTRICAL
TIGHTENING TORQUES
ENGINE
△- marked portion shall be checked for torque tightening after break-in or before each race.
Item Standard Limit
Ignition system:
Ignition timing (B.T.D.C.) 0.48 mm (0.019 in) ----
Advancer type Electrical ----
CDI:
Magneto-model (stator)/Manufacturer 1C3-10/YAMAHA ----
Charging coil 1 resistance (color) 720–1,080 Ωat 20 °C (68 °F) (Green/
White-Black/Red)----
Charging coil 2 resistance (color) 44–66 Ωat 20 °C (68 °F) (Black-Green/
Blue)----
Pickup coil resistance (color) 248–372 Ωat 20 °C (68 °F) (White/Blue-
White/Red)----
CDI unit-model/manufacturer 1C3-10/YAMAHA ----
Ignition coil:
Model/manufacturer 1C3-00/YAMAHA ----
Minimum spark gap 6 mm (0.24 in) ----
Primary winding resistance 0.24–0.36 Ωat 20 °C (68 °F) ----
Secondary winding resistance 5.7–8.5 kΩat 20 °C (68 °F) ----
Spark plug cap:
Resistance 4–6 kΩat 20 °C (68 °F) ----
Part to be tightened Thread size Q'tyTightening torque
Nm m•kg ft•lb
Spark plug M14S × 1.25 1 20 2.0 14
Cylinder head (nut) M8 × 1.25 5 28 2.8 20
Cylinder head (stud) M8 × 1.25 5 13 1.3 9.4
Cylinder (nut) M8 × 1.25 4 30 3.0 22
Cylinder (stud) M10 × 1.25 4 13 1.3 9.4
Power valve:
Cover M5 × 0.8 4 5 0.5 3.6
Link lever M4 × 0.7 1 4 0.4 2.9
Holder (power valve) M5 × 0.8 4 8 0.8 5.8
Push rod M5 × 0.8 1 5 0.5 3.6
Thrust plate M5 × 0.8 1 4 0.4 2.9
Governor fork M4 × 0.7 2 5 0.5 3.6
Housing M5 × 0.8 3 4 0.4 2.9
Water pump housing cover M6 × 1.0 4 10 1.0 7.2
Coolant drain bolt M6 × 1.0 1 10 1.0 7.2
Radiator M6 × 1.0 6 10 1.0 7.2
Radiator panel M6 × 1.0 2 10 1.0 7.2
Radiator hose clamp M6 × 1.0 8 2 0.2 1.4
Air filter element M6 × 1.0 1 2 0.2 1.4

6-3
IGNITION SYSTEM
IGNITION SYSTEM
INSPECTION STEPS
Use the following steps for checking the possibility of the malfunctioning engine being attributable to ignition system failure
and for checking the spark plug which will not spark.
*marked: Only when the ignition checker is used.
• Remove the following parts before inspection.
1. Seat
2. Fuel tank
• Use the following special tools in this inspection.
Spark gap test Spark→*Clean or replace spark plug.
No spark↓
Check entire ignition system for connection. No good→Repair or replace.
OK↓
Check engine stop switch. No good→Replace.
OK↓
Check ignition coil. (primary coil and secondary
coil)No good→
Replace.
OK↓
Check spark plug cap. No good→Replace.
OK↓
Check CDI magneto. (pickup coil and charging
coil)No good→
Replace.
OK↓
Replace CDI unit.
Dynamic spark tester:
YM-34487
Ignition checker:
90890-06754
Pocket tester:
YU-3112-C/90890-03112

6-5
IGNITION SYSTEM
CHECKING THE CDI MAGNETO
1. Inspect:
• Pickup coil resistance
Out of specification→Replace.
2. Inspect:
• Charging coil 1 resistance
Out of specification→Replace.3. Inspect:
• Charging coil 2 resistance
Out of specification→Replace.
CHECKING THE CDI UNIT
Check all electrical components. If no
fault is found, replace the CDI unit.
Then check the electrical compo-
nents again. Tester (+) lead→White/Red lead
"1"
Tester (-) lead→White/Blue lead
"2"
Pickup coil
resistanceTester se-
lector posi-
tion
248–372 Ω
at 20 °C (68
°F)Ω × 100
Tester (+) lead→Black/Red lead
"1"
Tester (-) lead→Green/White lead
"2"
Charging
coil 1 resis-
tanceTester se-
lector posi-
tion
720–1,080
Ω at 20 °C
(68 °F)Ω × 100
Tester (+) lead→Green/Blue lead
"1"
Tester (-) lead→Black lead "2"
Charging
coil 2 resis-
tanceTester se-
lector posi-
tion
44–66 Ω at
20 °C (68
°F)Ω × 10