2003 YAMAHA TTR125 engine

5 - 55
CHASSWINGARM
EC570000
SWINGARM
Extent of removal:1 Swingarm removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removalSWINGARM REMOVAL
Hold the machine by placing the
suitable stand under the engine.
WARNING
Support the machine securely so there is nodanger of it falling over.
Rear wheel Refer to “REAR WHEEL AND REAR
BRAKE” section.
1 Drive chain tensioner (upper) 1
2 Drive chain tensioner (lower) 1
3 Bolt (connecting arm-frame) 1
4 Bolt (rear shock absorber-relay arm) 1Hold the swingarm.
5 Pivot shaft 1
6 Swingarm 1
1

5 - 62
CHASREAR SHOCK ABSORBER ASSEMBLY
EC580000
REAR SHOCK ABSORBER ASSEMBLY
Extent of removal:1 Rear shock absorber assembly removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removalREAR SHOCK ABSORBER
ASSEMBLY REMOVAL
Hold the machine by placing the
suitable stand under the engine.
WARNING
Support the machine securely so there is nodanger of it falling over.
Seat and side covers Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section.
1 Bolt (rear shock absorber assem-
bly-relay arm)1 Hold the swingarm.
2 Bolt (rear shock absorber assem-
bly-frame)1
3 Bushing 1 Refer to “REMOVAL POINTS”.
4 Rear shock absorber assembly 1
1

6 - 1
–+ELEC
* The illustration shows the TT-R125LW
ELECTRICAL COMPONENTS AND WIRING DIAGRAM
EC600000
ELECTRICAL
EC610000
ELECTRICAL COMPONENTS AND WIRING DIAGRAM
EC611000
ELECTRICAL COMPONENTS
1CDI unit
2Engine stop switch
3Ignition coil
4CDI magneto
5Spark plugCOLOR CODE
B...................... Black
Br .................... Brown
G ..................... Green
O ..................... Orange
R ..................... Red
W..................... WhiteB/R .................. Black/Red
B/W ................. Black/White
G/L .................. Green/Blue
G/W ................. Green/White
W/L .................. White/Blue
W/R ................. White/Red
EC612000
WIRING DIAGRAM

–+ELEC
6 - 2
IGNITION SYSTEM
EC620000
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.
NOTE:
Remove the following parts before inspection.
1) Seat
2) Fuel tank
Use the following special tools in this inspection.
Spark gap test*Clean or replace
spark plug.
Check entire ignition
system for connection.Repair or replace.
Check engine stop switch. Replace.
Check ignition coil. Primary coil Replace.
Secondary coil Replace.
Check CDI magneto. Pickup coil Replace.
Charging coil Replace.
Replace CDI unit.
Dynamic spark tester:
YM-34487
Ignition checker:
90890-06754Pocket tester:
YU-3112-C/90890-03112
No Spark
OK
OK
OK
OK
Spark
No good
No good
No good
No good
No good
No good

6 - 3
–+ELECIGNITION SYSTEM
SPARK GAP TEST
1. Disconnect the spark plug cap from spark
plug.
2. Connect the dynamic spark tester 1
(ignition checker 2) as shown.
Spark plug cap 3
Spark plug 4
ÅFor USA and CDN
ıExcept for USA and CDN
3. Kick the kickstarter crank.
4. Check the ignition spark gap.
5. Start engine, and increase spark gap
until misfire occurs. (for USA and CDN
only)
Minimum spark gap:
6.0 mm (0.24 in)
Å
ı
EC624000
COUPLERS AND LEADS CONNECTION
INSPECTION
1. Check:
Couplers and leads connection
Rust/dust/looseness/short-circuit →
Repair or replace.
ENGINE STOP SWITCH INSPECTION
1. Inspect:
Engine stop switch conduct.
Not continuous while being pushed →
Replace.
Continuous while being freed → Replace. Tester (+) lead → Black/White lead 1
Tester (–) lead → Black lead 2
B/W
1B
2Tester selec-
tor position
PUSH IN
Ω × 1
FREE