light YAMAHA TTR90 2006 Owner's Manual

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ENGSHIFT FORK, SHIFT CAM AND TRANSMISSION
EC4H3000
REMOVAL POINTS
Shift fork, shift cam and transmission
1. Remove:
Shift forks
Shift cam
Drive axle assembly
Main axle assembly
NOTE:
Tap lightly on the transmission drive axle and
shift cam with a soft hammer to remove.
Remove assembly carefully. Note the posi-
tion of each part. Pay particular attention to
the location and direction of shift forks.
ASSEMBLY AND INSTALLATION
Transmission, shift cam shift fork
1. Install:
Main axle assembly 1
Drive axle assembly 2
2. Install:
Shift fork 1 “L” 1
Shift fork 2 “R” 2
Shift cam 3
Guide bar 4
NOTE:
The embossed marks on the shift forks should
face towards the right side of the engine and
be in the following sequence: “R”, “L”.
3. Check:
Shifter operation
Transmission operation
Unsmooth operation → Repair.

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5. Measure:
Brush length a
Out of specification → Replace.
Brush length wear limit:
3.5 mm (0.14 in)
6. Measure:
Brush spring force
Fatigue/out of specification → Replace as
a set.
Brush spring force:
3.92 ~ 5.88 N
(400 ~ 600 g, 14.1 ~ 21.2 oz)
ASSEMBLY
1. Install:
Brush holder
2. Install:
Armature coil 1
3. Install:
Ring 1
Stator assembly 2
Front bracket 3
NOTE:
Apply molybdenum grease lightly on to the
bearings of the starter motor.
Align the match mark on the yoke with the
match mark on the bracket.
ELECTRIC STARTING SYSTEM (TT-R90E)

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CHARGING SYSTEM (TT-R90E)
EC680000
CHARGING SYSTEM (TT-R90E)
EC681001
INSPECTION STEPS
If the battery is not charged, use the following inspection steps.
*1 marked: Refer to “FUSE INSPECTION” section in the CHAPTER 3.
*2 marked: Refer to “BATTERY INSPECTION AND CHARGING” section in the CHAPTER 3.
NOTE:
Remove the following parts before inspection.
1) Seat
2) Rear fender
3) Fuel tank
Use the following special tool in this inspection.
Pocket tester:
YU-3112-C/90890-03112Inductive tachometer:
YU-8036-B
Engine tachometer:
90890-03113
*1 Check fuse.Replace fuse and
check wire harness.
*2 Check battery. Recharge or replace.
Check each coupler and
wire connection.Repair or replace.
Check charging voltage.Charging system is
good.
Check CDI magneto. Lighting coil Replace.
Replace rectifier/regulator.
OK
OK
OK
No good
OK
No good
OK
No good
No good
No good

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–+ELECCHARGING SYSTEM (TT-R90E)
EC624000
COUPLERS AND LEADS CONNECTION
INSPECTION
1. Check:
Couplers and leads connection
Rust/dust/looseness/short-circuit →
Repair or replace.
CHARGING VOLTAGE INSPECTION
1. Start the engine.
2. Inspect:
Charging voltage
Out of specification → If no failure is
found in checking the source coil resis-
tance, replace the rectifier/regulator.
Tester (+) lead
→ Red lead
1
Tester (–) lead
→ Black lead
2
Charging
voltageTester selector
position
14.0 ~ 15.0 V at
5,000 r/minDCV-20
WB
R
Y/R
12
3. Inspect:
Lighting coil resistance
Out of specification → Replace.
Tester (+) lead
→ White lead
1
Tester (–) lead
→ Black lead
2
Lighting coil
resistanceTester selector
position
0.64 ~ 0.96
Ω at
20 °C (68 °F)Ω
× 1
WSb
YB
1
2

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CARBURETOR HEATING SYSTEM
CARBURETOR HEATING SYSTEM
INSPECTION STEPS
Use the following steps for checking the possibility of the malfunctioning carburetor heating system.
NOTE:
Remove the following parts before inspection.
1) Seat
2) Fuel tank
Use the following special tools in this inspection.
Pocket tester:
YU-3112-C/90890-03112
Check entire carburetor
heating system for connec-
tion.Repair or replace.
Check thermo switch. Replace.
Check carburetor heater. Replace.
Check CDI magneto. Lighting coil Replace.
Replace rectifier/regulator.
OK
OK
OK
OK
No good
No good
No good
No good

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–+ELECCARBURETOR HEATING SYSTEM
CARBURETOR HEATER INSPECTION
1. Inspect:
Carburetor heater resistance
Out of specification → Replace.
Tester (+) probe
→
Carburetor heater terminal
1
Tester (–) probe
→
Carburetor heater body
2
Carburetor
heater resistanceTester selector
position
6 ~ 10
Ω at
20 °C (68 °F)Ω
× 1
CDI MAGNETO INSPECTION
1. Inspect:
Lighting coil resistance
Out of specification → Replace.
ÈTT-R90
ÉTT-R90E
Tester (+) lead
→ Yellow lead
1
Tester (–) lead
→ Black lead
2
Lighting coil
resistanceTester selector
position
TT-R90:
0.28 ~ 0.42
Ω at
20 °C (68 °F)
TT-R90E:
0.52 ~ 0.78
Ω at
20 °C (68 °F)Ω
× 1
W
Y
B
WSb
YB
1
2
1
2
È
É