2004 YAMAHA TTR90 ignition

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

1 - 7
GEN
INFO
SPECIAL TOOLS
YM-1312-A, 90890-01312Fuel level gauge
This gauge is used to measure the fuel level in the
float chamber.YM-1312-A 90890-01312
YM-1326, 90890-01326 T-handle
This tool is used for holding the damper rod holder
when removing or installing the damper rod holder.YM-1326 90890-01326
90890-01186 Fork seal driver attachment
This tool is used to installing the oil seal.90890-01186
YM-8035, 90890-01311 Valve adjusting tool
This tool is necessary for adjusting valve clearance.YM-8035 90890-01311
YM-33963, 90890-01184 Fork seal driver weight
This tool is used to installing the oil seal.YM-33963 90890-01184
YM-34487
90890-06754Dynamic spark tester
Ignition checker
This instrument is necessary for checking the ignition
system components.YM-34487 90890-06754
YM-33975, 90890-01403 Ring nut wrench
This tool is used when tighten the steering ring nut to
specification.YM-33975 90890-01403
YM-91042, 90890-04086 Clutch holding tool
This tool is used to hold the clutch when removing or
installing the clutch boss securing nut.YM-91042 90890-04086
YS-1880-A, 90890-01701 Sheave holder
This tool is used for when loosening or tightening the
flywheel magneto securing nut.YS-1880-A 90890-01701
Part number Tool name/How to use Illustration

1 - 13
GEN
INFO
STARTING AND OPERATION
STARTING AND OPERATION
CAUTION:
Prior to operating the machine, perform
steps listed in pre-operation check list.
WARNING
Never start your engine or let it run for any
length of time in a closed area. The exhaust
fumes are poisonous and can cause loss of
consciousness and death within a short
time. Always operate your machine in an
area with adequate ventilation.
STARTING A COLD ENGINE
TT-R90
WARNING
Before starting the engine, be sure to shift
the transmission into neutral.
1. Turn the fuel cock to “ON”.
2. Operate the starter (choke) and com-
pletely close the throttle grip.
3. Slide the “ENGINE STOP” switch to the
“”.
4. Kick the kick starter with full strength to
start the engine.
5. After the engine starts, warm up for one
or two minutes. Make sure the stater
(choke) is returned to the original position
before riding.
TT-R90E
WARNING
Before starting the engine, be sure to shift
the transmission into neutral.
NOTE:
This model is equipped with an ignition cir-
cuit cut-off system. In case of electric start-
ing, the engine can be started only when the
transmission is in neutral.
If the engine fails to start by pushing the start
switch, release the switch, wait a few sec-
onds, and then try again. Each starting
attempt should be as short as possible to
preserve the battery. Do not crank the
engine more than 10 seconds on any one
attempt. If the engine does not start with the
starter motor, try using the kickstarter.1. Turn the fuel cock to “ON”.
2. Turn the main switch to “ON”.
3. Shift the transmission into neutral.
4. Operate the starter (choke) and com-
pletely close the throttle grip.
5. Start the engine by pushing the start
switch or by kicking the kickstarter.
6. After the engine starts, warm up for one
or two minutes. Make sure the stater
(choke) is returned to the original position
before riding.
STARTING A WARM ENGINE
To start a warm engine, refer to the “Starting a
cold engine” section. The starter (choke)
should not be used. The throttle should be
opened slightly.
CAUTION:
See “Engine break-in Section” prior to
operating engine for the first time.
WARMING UP
To get maximum engine life, always “warm-up”
the engine before starting off. Never accelerate
hard with a cold engine! To see whether or not
the engine is warm, see if it responds to throt-
tle normally with the stater (choke) turned off.
WARNING
Before starting off, be sure to turn up or
remove the side stand.
Failure to retract the side stand completely
can result in a serious accident when you
try to turn a corner.
ENGINE BREAK-IN
Brake-in is important to better fit the moving
and sliding parts as well as the installed parts.
It is also important to accustom the rider to the
machine better.
Avoid full-throttle run on a new machine for the
first 5 hours.
After the trial run, check for loose parts, oil
leakage and other problems.
Make full inspection and adjustment especially
of slack cables and drive chain and loose
spokes.
CAUTION:
After the break-in period, check every fit-
ting and fastener for looseness.
If any loose is found, retighten it securely.

SPEC

2 - 3 Transmission:
Primary reduction system Spur gear
Primary reduction ratio 67/18 (3.722)
Secondary reduction system Chain drive
Secondary reduction ratio 35/14 (2.500)
Transmission type Constant mesh, 3-speed
Operation Left foot operation
Gear ratio: 1st 37/13 (2.846)
2nd 33/19 (1.736)
3rd 28/23 (1.217)
Chassis:
Frame type Steel tube backbone
Caster angle 24.83˚
Trail 56.0 mm (2.2 in)
Tire:
Type With tube
Size (front) 2.50-14 4PR
Size (rear) 3.00-12 4PR
Manufacturer (front and rear) CHENG SHIN
Type (front and rear) KNOBBY
Tire pressure (front and rear) 100 kPa (1.00 kgf/cm
2

, 14.5 psi)
Brake:
Front brake type Drum brake
Operation Right hand operation
Rear brake type Drum brake
Operation Right foot operation
Suspension:
Front suspension Telescopic fork
Rear suspension Swingarm (monocross suspension)
Shock absorber:
Front shock absorber Coil spring/oil damper
Rear shock absorber Coil spring/gas, oil damper
Wheel travel:
Front wheel travel 110 mm (4.33 in)
Rear wheel travel 95 mm (3.74 in)
Electrical:
Ignition system CDI
Generator system (TT-R90E) CDI magneto
Battery type (TT-R90E) GT4B-5
Battery voltage/capacity (TT-R90E) 12 V/2.5 AH
Specific gravity (TT-R90E) 1.350
GENERAL SPECIFICATIONS

SPEC
2 - 14
EC212300
ELECTRICAL
TT-R90
Item Standard Limit
CDI:
Magneto-model/manufacturer F5HN 00/YAMAHA ----
Source coil resistance (color) 688 ~ 1,032 Ω at 20 ˚C (68 ˚F)
(Brown – Green)----
Pickup coil resistance (color) 248 ~ 372 Ω at 20 ˚C (68 ˚F)
(Red – White)----
CDI unit-model/manufacturer 4GL-20/YAMAHA ----
Ignition coil:
Model/manufacturer 2JN-00/YAMAHA ----
Minimum spark gap 6 mm (0.24 in) ----
Primary winding resistance 0.18 ~ 0.28 Ω at 20 ˚C (68 ˚F) ----
Secondary winding resistance 6.3 ~ 9.5 kΩ at 20 ˚C (68 ˚F) ----
Spark plug cap:
Type Resin ----
Resistance 10 kΩ at 20 ˚C (68 ˚F) ----
MAINTENANCE SPECIFICATIONS

SPEC
2 - 15 TT-R90E
Item Standard Limit
CDI:
Magneto-model/manufacturer F5HN/YAMAHA ----
Source coil resistance (color) 688 ~ 1,032 Ω at 20 ˚C (68 ˚F)
(Brown – Green)----
Pickup coil resistance (color) 248 ~ 372 Ω at 20 ˚C (68 ˚F)
(Red – White)----
CDI unit-model/manufacturer 5HN/YAMAHA ----
Ignition coil:
Model/manufacturer 2JN-00/YAMAHA ----
Minimum spark gap 6 mm (0.24 in) ----
Primary winding resistance 0.18 ~ 0.28 Ω at 20 ˚C (68 ˚F) ----
Secondary winding resistance 6.3 ~ 9.5 kΩ at 20 ˚C (68 ˚F) ----
Spark plug cap:
Type Resin ----
Resistance 10 kΩ at 20 ˚C (68 ˚F) ----
Charging system:
System type CDI magneto ----
Model/manufacturer F5HN/YAMAHA ----
Normal output 14 V/100 W at 5,000 r/min ----
Lighting coil 1 resistance (color) 0.64 ~ 0.96 Ω at 20 ˚C (68 ˚F)
(White – Black)----
Lighting coil 2 resistance (color) 0.52 ~ 0.78 Ω at 20 ˚C (68 ˚F)
(Yellow – Black)----
Rectifier/regulator:
Regulator type Semiconductor short circuit ----
Model/manufacturer SH620B-12/SHINDENGEN ----
No-load regulated voltage 14.0 ~ 15.0 V ----
Rectifier capacity 8 A ----
Electric starting system:
Type Constant mesh
Starter motor:
Model/manufacturer 5HN/YAMAHA ----
Operation voltage 12 V ----
Output 0.35 kW ----
Armature coil resistance 0.018 ~ 0.022 Ω at 20 ˚C (68 ˚F) ----
Brush overall length 7 mm (0.28 in) 3.5 mm
(0.14 in)
Brush quantity 2 pcs. ----
Spring force 3.92 ~ 5.88 N
(400 ~ 600 g, 14.1 ~ 21.2 oz)3.92 N
(400g,
14.1 oz)
Commutator diameter 17.6 mm (0.69 in) 16.6 mm
(0.65 in)
Mica undercut (depth) 1.35 mm (0.05 in) ----
MAINTENANCE SPECIFICATIONS

2 - 18
SPEC

CABLE ROUTING DIAGRAM
TT-R90
1
Crankcase breather hose
2
Wire harness
3
CDI magneto lead
4
Starter cable
5
Carburetor heating lead
6
Engine stop switch lead
7
Thermo switch
8
Thermo switch lead
9
Spark plug lead
0
Throttle cable
A
Cable holder
B
Fuel tank breather hose
C
Brake cable
Å
After fastening the starter cable, CDI magneto lead, wire harness and
thermo switch lead, cut off any excess from the plastic locking tie end.
ı
Pass the ignition coil lead through the lead guide.
Ç
Fasten the engine stop switch lead with the plastic bands.
Î
Pass the brake cable through the cable guides.
12345
9
0
B A
6
C 1Å
ı
Ç
Î
Î
A
A
67
8
20 ~ 30 mm
(0.79 ~ 1.18 in)

CABLE ROUTING DIAGRAM

2 - 19
SPEC

1
Cable guide
2
Brake cable
3
Throttle cable
4
Fuel tank breather hose
5
Engine stop switch lead
6
Air vent hose
7
Air intake duct
8
Ignition coil
9
Cable guide
0
Wire harness
A
Damper
B
CDI unit lead
C
CDI unit
D
Rectifier/regulator lead
E
Rectifier/regulator
F
Crankcase breather hose
G
Carburetor breather hose
H
Spark plug lead
I
Fuel hose
J
Starter cable
K
CDI magneto lead
L
Thermo switch
A
123
4
5
6
7
8
9
0A
C
E B
F G H I
6
6 J L
5
H
B8 K
7 ÅÇ
‰
Ç
Ï
Ì
B - B C - C
D - DF - FE
ı
Î
D
D
B
D
A A B
B B
B
C
C C
CE
B D
B
D
F F F F

CABLE ROUTING DIAGRAM