2006 YAMAHA YZ125LC ignition

CHAPTER 6
ELECTRICAL
ELECTRICAL COMPONENTS AND
WIRING DIAGRAM.....................................6-1
IGNITION SYSTEM.....................................6-2
CHAPTER 7
TUNING
ENGINE.......................................................7-1
CHASSIS...................................................7-13
1C3-9-31-0 4/28/05 4:32 PM Page 22

1-7
GEN
INFO
SPECIAL TOOLS
EC140002
SPECIAL TOOLS
The proper special tools are necessary for complete and accurate tune-up and assembly. Using the
correct special tool will help prevent damage caused by the use of improper tools or improvised tech-
niques. The shape and part number used for the special tool differ by country, so two types are provid-
ed. Refer to the list provided to avoid errors when placing an order.
NOTE:
9For U.S.A. and Canada, use part number starting with “YM-”, “YU-” or “ACC-”.
9For others, use part number starting with “90890-”.
Part number Tool name / How to use IIIustration
YU-1135-A, 90890-01135Crankcase separating toolYU-1135-A 90890-01135
These tool is used to split the crankcase as well
as remove the crankshaft from either case.
YM-1189, 90890-01189 Flywheel puller
YM-1189 90890-01189
This tool is used to remove the flywheel magneto.
YU-1235, 90890-01235 Rotor holding tool
YU-1235 90890-01235
This tool is used when loosening or tightening the
flywheel magneto securing nut.
YU-3097, 90890-01252 Dial gauge and stand
YU-3097 90890-01252
YU-1256 Spark plug hole dial standYU-1256
These tools are used to set the ignition timing.
Crankcase installing tool
YU-90050 90890-01274
YU-90050, 90890-01274 PotYU-90063 90890-01275
YU-90050, 90890-01275 BoltYM-0149990890-01278
YU-90063, 90890-01278 Adapter90890-01499
YM-01499, 90890-01499 Adapter
These tools are used to install the crankshaft.
YU-1304, 90890-01304 Piston pin puller
YU-1304 90890-01304
This tool is used to remove the piston pin.
YM-1312-A, 90890-01312Fuel level gaugeYM-1312-A 90890-01312
YM-01470, 90890-01470 Fuel level gauge adaptorYM-01470 90890-01470
This gauge is used to measure the fuel level in the
float chamber.
1C3-9-31-1A 4/21/05 10:54 AM Page 14

1-8
GEN
INFO
SPECIAL TOOLS
Part number Tool name / How to use IIIustration
YU-24460-01, 90890-01325Radiator cap testerYU-24460-01 90890-01325
YU-33984, 90890-01352 AdapterYU-33984 90890-01352
These tools are used for checking the cooling
system.
YU-33270-B, 90890-01362Flywheel puller
YU-33270-B 90890-01362
These tool is used to split the crankcase.
YU-33975, 90890-01403 Ring nut wrench
YU-33975 90890-01403
This tool is used when tighten the steering ring nut
to specification.
YM-01500, 90890-01500 Cap bolt wrench
YM-01500 90890-01500
This tool is used to loosen or tighten the base valve.
YM-01501, 90890-01501 Cap bolt ring wrench
YM-01501 90890-01501
This tool is used to loosen or tighten the damper
assembly.
YM-A0948, 90890-01502 Fork seal driver
YM-A0948 90890-01502
This tool is used when install the fork oil seal.
YU-3112-C, 90890-03112 Yamaha pocket tester
YU-3112-C 90890-03112
Use this tool to inspect the coil resistance,
output voltage and amperage.
YM-91042, 90890-04086 Clutch holding tool
YM-91042 90890-04086
This tool is used to hold the clutch when removing
or installing the clutch boss securing nut.
YM-34487 Dynamic spark tester
YM-34487 90890-06754
90890-06754 Ignition checker
This instrument is necessary for checking the igni-
tion system components.
ACC-QUICK-GS-KT Quick gasket
®ACC-QUICK-GS-KT 90890-85505
90890-85505 YAMAHA Bond No. 1215
This sealant (Bond) is used for crankcase mating
surface, etc.
1C3-9-31-1A 4/21/05 10:54 AM Page 15

2-2
SPECGENERAL SPECIFICATIONS
Carburetor:
Type/Manufacturer TMXχ
38SS/MIKUNI
Spark plug:
Type/Manufacturer BR9EVX/NGK (resistance type)
Gap 0.6~0.7 mm (0.024~0.028 in)
Clutch type: Wet, multiple-disc
Transmission:
Primary reduction system Gear
Primary reduction ratio 64/19 (3.368)
Secondary reduction system Chain drive
Secondary reduction ratio 48/13 (3.692)
Transmission type Constant mesh, 6-speed
Operation Left foot operation
Gear ratio: 1st 31/13 (2.385)
2nd 29/15 (1.933)
3rd 27/17 (1.588)
4th 23/17 (1.353)
5th 24/20 (1.200)
6th 23/21 (1.095)
Chassis:USA, ZA, AUS, NZEUROPE,CDN
Frame type Semi double cradle←
Caster angle 25.5° 25.6°
Trail 105 mm (4.13 in) 107 mm (4.21 in)
T ire:
Type With tube
Size (front) 80/100-21 51M
Size (rear) 100/90-19 57M
T ire pressure (front and rear) 100 kPa (1.0 kgf/cm2, 15 psi)
Brake:
Front brake type Single disc brake
Operation Right hand operation
Rear brake type Single disc brake
Operation Right foot operation
Suspension:
Front suspension Telescopic fork
Rear suspension Swingarm (link type monocross suspension)
Shock absorber:
Front shock absorber Coil spring/oil damper
Rear shock absorber Coil spring/Gas, oil damper
Wheel travel:
Front wheel travel 300 mm (11.8 in)
Rear wheel travel 315 mm (12.4 in)
Electrical:
Ignition system CDI magneto
2
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2-11
SPECMAINTENANCE SPECIFICATIONS
EC212300
ELECTRICAL
Part to be tightened Thread size Q’tyT ightening torqueNm m•kg ft•lb
Stator M 6 ×1.0 3 7 0.7 5.1
Rotor M12 ×1.25 1 56 5.6 40
Ignition coil M 6 ×1.0 2 7 0.7 5.1
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…
Source coil 1 resistance (color) 720~1,080 Ωat 20°C (68°F)…
(Green/White-Black/Red)
Source 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 5.7~8.5kΩat 20°C (68°F)…
Spark plug cap:
Resistance 4~6 kΩat 20°C (68°F)…
1C3-9-31-2A 4/30/05 2:37 PM Page 12

2-13
SPECCABLE ROUTING DIAGRAM
EC240000
CABLE ROUTING DIAGRAM
1“ENGINE STOP” button lead
2Throttle cable
3Clutch cable
4Ground lead
5High tension cord
6Clamp
7Air vent hose
8Radiator breather hose
9CDI magneto lead
0YPVS breather hose
qEngine bracket (right)
wEngine bracket (left)
eCrankcase breather hose
rOverflow hose
tConnector coverAPass the clutch cable on the
outside of the throttle cable and
“ENGINE STOP” button lead.
BAlign the throttle cable locating
tape with the cable guide.
CPass the throttle cable, clutch
cable and “ENGINE STOP”
button lead above the radiator
hose.
DInstall the ignition coil, side
core and ground lead together
to the frame. Take care to fas-
ten the ground lead so that its
terminal is within the indicated
range.
EClamp the throttle cable and
high tension cord to the frame.FClamp the clutch cable to the
left engine bracket. Clamp the
clutch cable below the posi-
tioning grommet.
GPass the air vent hose back of
the throttle cable.
HPass the air vent hose, over-
flow hose and crankcase
breather hose between the
frame and connecting rod.
IPass the radiator breather
hose and YPVS breather hose
outside the engine bracket and
inside the down tube. Then
pass the radiator breather
hose inside the YPVS breather
hose.
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2-15
SPECCABLE ROUTING DIAGRAM
1High tension cord
2“ENGINE STOP” button lead
3Ignition coil lead
4Clamp
5CDI unit
6CDI unit band
7Radiator breather hose
8CDI magneto lead
9Connector cover
0Throttle cable
qClutch cable
wCDI unit stay
APass the high tension cord to
the left of the radiator hose.
BUsing a plastic locking tie,
clamp the “ENGINE STOP”
button lead, ignition coil leadand CDI magneto lead togeth-
er with the clamp ends back-
ward and then cut off the tie
end.
CClamp to the frame the throttle
cable, clutch cable, ignition coil
lead and “ENGINE STOP” but-
ton lead. In so doing, clamp
the ignition coil lead and
“ENGINE STOP” button lead at
their protecting tubes. Tighten
the clamp so that the “ENGINE
STOP” button lead is not
pulled when the handlebar is
turned to the right and left.
DPass the CDI magneto lead
and radiator breather hose
between the frame and the
radiator(right).EClamp the CDI magneto lead
to the frame at its locating
tape.
FBring the connector cover into
contact with the coupler.
GLocate the clamp ends in the
arrowed range.
HInsert the CDI unit band until it
stops at the CDI unit stay.
IPass the CDI magneto lead
and radiator breather hose
between the frame and the
radiator hose so that they
come within the arrow-indicat-
ed range. Also take care so
that the CDI magneto lead
passes on the left of the radia-
tor breather hose.
1C3-9-31-2B 5/11/05 9:50 AM Page 30

3-4
PRE-OPERATION INSPECTION AND MAINTENANCE
INSP
ADJ
EC320000
PRE-OPERATION INSPECTION AND MAINTENANCE
Before riding for break-in operation, practice or a race, make sure the machine is in good operating
condition.
Before using this machine, check the following points.
EC321000
GENERAL INSPECTION AND MAINTENANCE
Item Routine Page
Coolant Check that coolant is filled up to the radiator filler cap.
Check the cooling system for leakage.P3-5~9
Fuel Check that a fresh mixture of oil and gasoline is filled in
the fuel tank. Check the fuel line for leakage.P1-12
Transmission oil Check that the oil level is correct. Check the crankcase
for leakage.P3-12~14
Gear shifter and clutch Check that gears can be shifted correctly in order and
that the clutch operates smoothly.P3-9
Throttle grip/Housing Check that the throttle grip operation and free play
are correctly adjusted. Lubricate the throttle grip and P3-10~11
housing, if necessary.
Brakes Check the play of front brake and effect of front and
rear brake.P3-17~23
Chain Check chain slack and alignment. Check that the chain
is lubricated properly.P3-24~26
Wheels Check for excessive wear and tire pressure. Check for
loose spokes and have no excessive play.P3-34~35
Steering Check that the handlebar can be turned smoothly and
have no excessive play.P3-35~36
Front forks and Check that they operate smoothly and there is no oil
rear shock absorber leakage.P3-26~33
Cables (wires) Check that the clutch and throttle cables move smooth-
ly. Check that they are not caught when the handlebars —
are turned or when the front forks travel up and down.
Muffler Check that the muffler is tightly mounted and has no
cracks.P3-15~16
Sprocket Check that the driven sprocket tightening bolt is
not loose.P3-24
Lubrication Check for smooth operation. Lubricate if necessary. P3-37
Bolts and nuts Check the chassis and engine for loose bolts and nuts. P1-16
Lead connectors Check that the CDI magneto, CDI unit, and ignition coil
are connected tightly.P1-6
Settings Is the machine set suitably for the condition of the
racing course and weather or by taking into account the
P7-1~23
results of test runs before racing? Are inspection and
maintenance completely done?
1C3-9-31-3A 4/28/05 2:48 PM Page 14