2003 YAMAHA TTR90 diagram

EC083000
MANUAL FORMAT
All of the procedures in this manual are organized in a sequential, step-by-step format. The informa-
tion has been complied to provide the mechanic with an easy to read, handy reference that contains
comprehensive explanations of all disassembly, repair, assembly, and inspection operations.
In this revised format, the condition of a faulty component will precede an arrow symbol and the
course of action required will follow the symbol, e.g.

Bearings
Pitting/damage
→
Replace.
EC084002
HOW TO READ DESCRIPTIONS
To help identify parts and clarify procedure steps, there are exploded diagrams at the start of each
removal and disassembly section.
1. An easy-to-see exploded diagram
1
is provided for removal and disassembly jobs.
2. Numbers
2
are given in the order of the jobs in the exploded diagram. A number that is
enclosed by a circle indicates a disassembly step.
3. An explanation of jobs and notes is presented in an easy-to-read way by the use of symbol
marks
3
. The meanings of the symbol marks are given on the next page.
4. A job instruction chart
4
accompanies the exploded diagram, providing the order of jobs,
names of parts, notes in jobs, etc.
5. Extent of removal
5
is provided in the job instruction chart to save the trouble of an unneces-
sary removal job.
6. For jobs requiring more information, the step-by-step format supplements
6
are given in addi-
tion to the exploded diagram and job instruction chart.

AUFBAU
Diese Anleitung wurde zusammengestellt, um
dem Benutzer ein leicht verständliches Nach-
schlagewerk in die Hand zu geben, in dem alle
dargestellten Arbeitsvorgänge (Ein- und Aus-
bau, Zerlegung und Zusammenbau, Prüfung
und Reparatur) detailliert und in der entspre-
chenden Reihenfolge beschrieben sind.
Je nach Zustand eines fehlerhaften Bauteils
weist ein Pfeilsymbol auf die erforderliche
Maßnahme hin. Beispiel:

Lager
Pitting/Beschädigung
→
Erneuern.
LESEN DER BESCHREIBUNGEN
Um bei der Identifikation der Teile zu helfen
und die Arbeitsschritte zu verdeutlichen, sind
Explosionsdiagramme am Beginn jedes Aus-
bau- und Demontageabschnittes dargestellt.
1. Für die Ausbau- und Demontagearbeiten
ist meistens ein übersichtliches Explosi-
onsdiagramm
1
dargestellt.
2. Die Nummern
2
in dem Explosionsdia-
gramm sind in der Reihenfolge der Arbei-
ten aufgeführt. Eine in einen Kreis
eingeschriebene Nummer bezeichnet
einen Demontageschritt.
3. Eine Erläuterung der Arbeiten und Hin-
weise ist durch ablesefreundliche Symbol-
markierungen
3
gegeben. Die
Bedeutungen der Symbolmarkierungen
sind auf der nächsten Seite aufgeführt.
4. Eine Arbeitsanweisungstabelle
4
beglei-
tet das Explosionsdiagramm und gibt die
Arbeitsreihenfolge, Bezeichnung der Teile,
Hinweise zu den Arbeiten usw. an.
5. Der Umfang des Ausbaus
5
ist in der
Arbeitsanweisungstabelle aufgeführt, um
nicht erforderliche Ausbauarbeiten zu ver-
meiden.
6. Für Arbeiten, für die weitere Informationen
benötigt werden, sind schrittweise Ergän-
zungen
6
zusätzlich zu dem Explosions-
diagramm und der
Arbeitsanweisungstabelle aufgeführt.
FORMAT DU MANUEL
Dans ce manuel, toutes les procédures sont décrites
pas à pas. Les informations ont été condensées pour
fournir à l’utilisateur un guide pratique et facile à
lire, contenant des explications claires pour toutes
les procédures de démontage, réparation, remon-
tage et vérification.
Dans ce nouveau format, l’état d’un composant
défectueux est suivi d’une flèche qui indique les
mesures à prendre. Exemple:

Roulements
Piqûres/endommagement
→
Remplacer.
COMMENT LIRE LES DESCRIP-
TIONS
Chaque section détaillant des étapes de démontage
ou de remontage est précédée de vues en éclaté qui
permettent de clarifier ces opérations.
1. Exemple de vue en éclaté
1
clarifiant les opé-
rations de démontage et de remontage.
2. Sur les vues en éclaté, les pièces sont numéro-
tées
2
dans l’ordre des opérations à effectuer.
Un chiffre entouré d’un cercle correspond à une
étape de démontage.
3. Les vues en éclaté portent également des sym-
boles
3
qui rappellent des points importants à
ne pas oublier. La signification de ces symboles
est expliquée à la page suivante.
4. Les vues en éclaté sont suivies d’un tableau
4
fournissant l’ordre des opérations, le nom des
pièces, des remarques, etc.
5. Pour éviter la dépose superflue de pièces,
l’étendue de la dépose 5 est indiquée dans le
tableau de description du travail.
6. Pour les travaux qui demandent des explica-
tions supplémentaires, la vue en éclaté et le
tableau sont suivis d’une description détaillée
6 des opérations.

ILLUSTRATED SYMBOLS
(Refer to the illustration)
Illustrated symbols
1
to
6
are designed as
thumb tabs to indicate the chapter’s number
and content.
1
General information
2
Specifications
3
Regular inspection and adjustments
4
Engine
5
Chassis
6
Electrical
Illustrated symbols
7
to
D
are used to identify
the specifications appearing in the text.
7
With engine mounted
8
Special tool
9
Filling fluid
0
Lubricant
A
Tightening
B
Specified value, Service limit
C
Engine speed
DResistance (Ω), Voltage (V), Electric current (A)
Illustrated symbols E to H in the exploded
diagram indicate grade of lubricant and loca-
tion of lubrication point.
EApply engine oil
FApply molybdenum disulfide oil
GApply lightweight lithium-soap base grease
HApply molybdenum disulfide grease
Illustrated symbols I to J in the exploded
diagrams indicate where to apply a locking
agent and when to install new parts.
IApply locking agent (LOCTITE®)
JUse new one 12
34
56
78
90
AB
CD
E F
G H
IJ
GEN
INFOSPEC
INSP
ADJENG
CHAS–+ELEC
T R..
EM
LSM
LTNew

CONTENTS
CHAPTER 1
GENERAL INFORMATION
DESCRIPTION
...........................................1-1
MACHINE IDENTIFICATION
.....................1-2
IMPORTANT INFORMATION
....................1-3
CHECKING OF CONNECTION
.................1-5
SPECIAL TOOLS
......................................1-6
CONTROL FUNCTIONS
............................1-9
FUEL
........................................................1-12
STARTING AND OPERATION
................1-13
CHAPTER 2
SPECIFICATIONS
GENERAL SPECIFICATIONS
...................2-1
MAINTENANCE SPECIFICATIONS
..........2-4
GENERAL TORQUE
SPECIFICATIONS
...................................2-16
DEFINITION OF UNITS
...........................2-16
CABLE ROUTING DIAGRAM
.................2-17
CHAPTER 3
REGULAR INSPECTION AND
ADJUSTMENTS
MAINTENANCE INTERVALS
...................3-1
PERIODIC MAINTENANCE
AND LUBRICATION
..................................3-1
PRE-OPERATION INSPECTION
AND MAINTENANCE
................................3-2
ENGINE
......................................................3-3
CHASSIS
.................................................3-11
ELECTRICAL
...........................................3-19

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
AND STARTER CLUTCH
........................4-39
CRANKCASE AND CRANKSHAFT
........4-43
SHIFT FORK, SHIFT CAM
AND TRANSMISSION
.............................4-46
CHAPTER 5
CHASSIS
FRONT WHEEL AND REAR WHEEL
.......5-1
FRONT FORK
............................................5-6
HANDLEBAR
.............................................5-9
STEERING
...............................................5-10
SWINGARM
.............................................5-11
CHAPTER 6
ELECTRICAL
ELECTRICAL COMPONENTS
AND WIRING DIAGRAM
...........................6-1
IGNITION SYSTEM
....................................6-2
ELECTRIC STARTING SYSTEM
..............6-6
CHARGING SYSTEM
..............................6-14
CARBURETOR HEATING SYSTEM
.......6-16
MAINTENANCE RECORD
......................6-19

2 - 17
SPEC

CABLE ROUTING DIAGRAM
CABLE ROUTING DIAGRAM
1
Crankcase breather hose
2
CDI magneto lead
3
Wire harness
4
Thermo switch
5
Thermo switch lead
6
CDI unit lead
7
Spark plug lead
8
Starter cable
9
Starter relay lead
0
Starter motor lead
A
Starter motor
B
Throttle cable
C
Brake cable
D
Engine stop switch lead
E
Main switch lead
F
Start switch lead
Å
Pass the spark plug lead
through the lead guide.
ı
Make sure that the starter cable
does not contact the engine
bracket.
Ç
Fasten the engine stop lead with
the plastic bands.
Î
Pass the brake cable through
the cable guide.
‰
Fasten the start switch lead with
the plastic bands.
30 ~ 40 mm
(1.18 ~ 1.57 in)A
B
40 ~ 50 mm
(1.57 ~ 1.97 in)
1
B
C
D
E ‰
F
ÎÎÇ A875 4
6 3
2
1
Å
ı
A
B
0
9

2 - 18
SPEC

CABLE ROUTING DIAGRAM
1
Clamp
2
Engine stop switch lead
3
Main switch lead
4
Start switch lead
5
Brake cable
6
Throttle cable
7
Fuel tank breather hose
8
Ignition coil
9
Wire harness
0
Starter relay
A
Starter motor lead
B
Crankcase breather hose
C
Starter motor lead
D
Neutral switch lead
E
CDI magneto lead
F
CDI unit
G
Fuel overflow hose
HSpark plug lead
IFuel hose
JCarburetor heater lead
KCarburetor breather hose
LCarburetor heater couplerMCDI magneto coupler
NCDI unit coupler
OCDI unit connector
PCDI unit lead
QThermo switch lead
RThermo switch
SStarting circuit cut-off relay
TStarting circuit cut-off relay lead
URectifier/regulator lead
VRectifier/regulator
WStarter relay lead
A AA
C C
D
B
B B
BF FF
EE
D
A - AB - BE - E
C
F - FG - GD
KK
QRÔ
8
E
H
˜ 2 3 4
6
5
4
3
2
1
J
I
H
G
F
E
D
CBA 0 Ï 9 8 Î K 7
S
W U
V
A
0
Í T 99
QP
PT
9 
Ò
ˆ Ø
Ç ı
Å
Ó
Œ
Â
E
GGA
P
O
NML 9
È
9
Ì
Ê
Ë
25 mm (1.0 in)
∏
‰

2 - 19
SPECCABLE ROUTING DIAGRAM
ÅPass the start switch lead, main
switch lead, engine stop switch
lead and throttle cable through
the cable guide.
ıPass the fuel tank breather hose
through the hose guide.
ÇPass the carburetor breather
hose through the hose guide.
ÎFasten the carburetor heater lead,
main switch lead, engine stop
switch lead and start switch lead.‰After fastening the CDI mag-
neto lead, cut off any excess
from the plastic locking tie end.
ÏFasten the battery leads to the
bracket with the plastic locking
tie. For fastening, pass the plas-
tic locking tie through the hole in
the bracket.
ÌAfter fastening the starter motor
lead, cut off any excess from the
plastic locking tie end.ÓAfter fastening the CDI mag-
neto lead, cut off any excess
from the plastic locking tie end.
ÈPosition the start switch coupler
and engine stop switch coupler
between the carburetor breather
hose and thermo switch.
ÔMake sure that the CDI unit lead
does not contact the thermo
switch bracket.
A AA
C C
D
B
B B
BF FF
EE
D
A - AB - BE - E
C
F - FG - GD
KK
QRÔ
8
E
H
˜ 2 3 4
6
5
4
3
2
1
J
I
H
G
F
E
D
CBA 0 Ï 9 8 Î K 7
S
W U
V
A
0
Í T 99
QP
PT
9 
Ò
ˆ Ø
Ç ı
Å
Ó
Œ
Â
E
GGA
P
O
NML 9
È
9
Ì
Ê
Ë
25 mm (1.0 in)
∏
‰