Page 24 of 364

CHAPTER 4
ENGINE
CARBURETOR
..........................................4-1
CYLINDER HEAD
......................................4-8
CAMSHAFT AND ROCKER ARMS
........4-13
VALVES AND VALVE SPRINGS
............4-16
CYLINDER AND PISTON
........................4-21
CLUTCH
...................................................4-27
KICK AXLE
..............................................4-33
SHIFT SHAFT
..........................................4-34
OIL PUMP
................................................4-36
CDI MAGNETO (TT-R90)
........................4-39
CDI MAGNETO AND STARTER
CLUTCH (TT-R90E)
.................................4-41
CRANKCASE AND CRANKSHAFT
........4-45
SHIFT FORK, SHIFT CAM AND
TRANSMISSION
......................................4-48
CHAPTER 5
CHASSIS
FRONT WHEEL AND REAR WHEEL
.......5-1
FRONT FORK
............................................5-6
HANDLEBAR
.............................................5-9
STEERING
...............................................5-11
SWINGARM
.............................................5-12
CHAPTER 6
ELECTRICAL
ELECTRICAL COMPONENTS AND
WIRING DIAGRAM
....................................6-1
IGNITION SYSTEM
....................................6-3
ELECTRIC STARTING SYSTEM
(TT-R90E)
..................................................6-7
CHARGING SYSTEM (TT-R90E)
............6-15
CARBURETOR HEATING SYSTEM
.......6-17
MAINTENANCE RECORD
......................6-21
Page 312 of 364
6 - 1
–+ELECELECTRICAL COMPONENTS AND WIRING DIAGRAM
EC600000
ELECTRICAL
EC610000
ELECTRICAL COMPONENTS AND WIRING DIAGRAM
TT-R90
EC611000
ELECTRICAL COMPONENTS
1CDI magneto
2CDI unit
3Ignition coil
4Spark plug
5“ENGINE STOP” switch
6Thermo switch
7Carburetor heater
8Rectifier/regulatorCOLOR CODE
B...................... Black
Br .................... Brown
G ..................... Green
O ..................... Orange
R ..................... Red
W..................... White
EC612000
WIRING DIAGRAM
G/WB/RW/LW/RBr G
RW
WB
Y/R
O
BO
B
B
BY/RY
WY/RB
W
Y
B
GG/W
B/W
B/W
BrB/RWWWY
OO
BBW/LY/RR
W
B
B
B
W/R
Y/R
OFF
RUN
B
Y/R
B
B
Y
Y
1
23
4
5 6
7 8
B/R ................... Black/Red
B/W .................. Black/White
G/W.................. Green/White
W/L .................. White/Blue
W/R .................. White/Red
Page 314 of 364

6 - 2
–+ELEC
12
3
456
7
0
98
A
B
F
EC
D
ELECTRICAL COMPONENTS AND WIRING DIAGRAM
TT-R90E
EC611000
ELECTRICAL COMPONENTS
1Main switch
2“ENGINE STOP”
switch
3Thermo switch
4Ignition coil
5CDI unit
6Battery
7Rectifier/regulator
8Neutral switch9CDI magneto
0Carburetor heater
AStarter relay
BFuse
CStart switch
DSpark plug
EStarter motor
FStarting circuit cut-off
relayCOLOR CODE
B ...................... Black
Br .................... Brown
G ..................... Green
O ..................... Orange
R ..................... Red
Sb .................... Sky blue
W ..................... White
Y ...................... Yellow
EC612000
WIRING DIAGRAM
G/WB/RW/LW/RBr G
RW
B/WBr BRB/WBBrR
B/WB/WBB
BR/WBr B
GG/W
B/W
B/W
BrB/RWWOO
B
BW/LY/RR
W
B
B
R
W/RY/R
OFF RUNB
Y/R
Y
Y
OBO BY/RYB B
Sb
W W
Sb
ON OFF
OFFON
Y
BBY/R
Br
Br
B
B
R
RR
R
B
R/WR/W
R/WR/W
R/W
Sb
Sb
RB
R/WB R
Y/RRB W
B/WB
R/W
R/W
R/W
Sb
9
8
1 B5
4
D
2 3
=A
E 6
C
F 7
B/R ................... Black/Red
B/W .................. Black/White
G/W.................. Green/White
R/W .................. Red/White
W/L .................. White/Blue
W/R .................. White/Red
Y/R ................... Yellow/Red