GEN
INFO
1 - 13
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 completely
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 completely
close the throttle grip.
5. Slide the “ENGINE STOP” switch to the
“”.
6. Start the engine by pushing the start switch
or by kicking the kickstarter.
7. 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 throttle
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 - 13
NOTE:
1. First, tighten the ring nut approximately 38 Nm (3.8 m kg, 27 ft lb) by using the ring nut
wrench and turn the steering right and left a few times; then loosen the ring nut one turn.
2. Retighten the ring nut 1 Nm (0.1 m kg, 0.7 ft lb).
-marked portion shall be checked for torque tightening after break-in or before each ride.Part to be tightened Thread size Q’tyTightening torque
Nm m·kg ft·lb
Engine mounting:
Engine and frame (front-upper) M8 × 1.25 1 30 3.0 22
Engine and frame (rear-upper) M8 × 1.25 1 26 2.6 19
Engine and frame (rear-lower) M10 × 1.25 1 48 4.8 35
Starter cable and frame M11 × 1.25 1 1 0.1 0.7
Pivot shaft and nut M10 × 1.25 1 30 3.0 22
Handle crown and steering shaft M10 × 1.25 1 40 4.0 29
Front fork cap bolt M20 × 1.0 2 40 4.0 29
Under bracket and front fork M10 × 1.25 2 33 3.3 24
Damper rod bolt M8 × 1.25 2 20 2.0 14
Handle crown and handlebar holder (lower) M10 × 1.25 2 40 4.0 29
Handlebar holder (upper)(TT-R90) M6 × 1.0 4 13 1.3 9.4
(TT-R90E) M8 × 1.25 4 23 2.3 17
Front brake cable holder and front fork M6 × 1.0 2 7 0.7 5.1
Steering ring nut M25 1 Refer to NOTE.
Fuel tank and fuel cock M6 × 1.0 2 7 0.7 5.1
Fuel tank and frame M6 × 1.0 2 7 0.7 5.1
Grab bar and frame M6 × 1.0 4 13 1.3 9.4
Brake lever mounting (bolt) M6 × 1.0 1 3 0.3 2.2
Brake lever mounting (nut) M6 × 1.0 1 4 0.4 2.9
Front brake camshaft lever and camshaft M6 × 1.0 1 7 0.7 5.1
Rear brake camshaft lever and camshaft M6 × 1.0 1 7 0.7 5.1
Front wheel axle nut M10 × 1.25 1 35 3.5 25
Rear brake shoe plate tension bar M8 × 1.25 2 26 2.6 19
Wheel drive hub and driven sprocket M8 × 1.25 4 25 2.5 18
Rear wheel axle nut M12 × 1.25 1 60 6.0 43
Wheel nipple (spoke)—64 2 0.2 1.4
Drive chain guard M5 × 0.8 2 4 0.4 2.9
Drive chain support M5 × 0.8 3 4 0.4 2.9
Chain puller locknut M6 × 1.0 2 7 0.7 5.1
Footrest and frame M8 × 1.25 2 30 3.0 22
Battery box (TT-R90E) M6 × 1.0 3 5 0.5 3.6
MAINTENANCE SPECIFICATIONS
2 - 23
SPECCABLE ROUTING DIAGRAM
ÈPass the start switch lead,
main switch lead, engine stop
switch lead and throttle cable
through the cable guide.
ÉPass the fuel tank breather
hose through the hose guide.
ÊPass the carburetor breather
hose through the hose guide.
ËFasten the carburetor heater
lead, main switch lead, engine
stop switch lead and start
switch lead.ÌAfter fastening the CDI mag-
neto lead, cut off any excess
from the plastic locking tie end.
ÍFasten the battery leads to the
bracket with the plastic locking
tie. For fastening, pass the
plastic locking tie through the
hole in the bracket.
ÎAfter fastening the starter
motor lead, cut off any excess
from the plastic locking tie end.ÏAfter fastening the CDI mag-
neto lead, cut off any excess
from the plastic locking tie end.
ÐPosition the start switch cou-
pler and engine stop switch
coupler between the carburetor
breather hose and thermo
switch.
ÑMake 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
QRÑ
8
E
H
Ô 2 3 4
6
5
4
3
2
1
J
I
H
G
F
E
D
CBA 0 Í 9 8 Ë K 7
S
W U
V
A
0
Ú T
99
QP
PT
9 Ò
Ó
Õ Ö
Ê É
È
Ï
Ø
Ù
E
GGA
P
O
NML 9
Ð
9
Î
Û
Ý
25 mm (1.0 in)
×
Ì
35 ~ 45 mm
(1.38 ~ 1.77 in)
30 ~ 40 mm
(1.18 ~ 1.57 in)
Ü
2 - 24
SPECCABLE ROUTING DIAGRAM
ÒFasten the starter cable,
thermo switch lead, CDI unit
lead, main switch lead, start
switch lead and engine stop
switch lead.
ÓFasten the wire harness, CDI
unit leads, thermo switch lead
and CDI magneto lead.
ÔPass the carburetor heater
lead between the carburetor
breather hose and air intake
duct.ÕPosition the main switch cou-
pler between the carburetor
breather hose and air intake
duct.
ÖFasten the start switch lead,
main switch lead and engine
stop switch lead at the tape
with the plastic locking tie.
×Fasten the battery leads.ØFasten the wire harness and
starting circuit cut-off relay lead
at the tape for the wire harness
with the plastic locking tie.
ÙFasten the rectifier/regulator
lead and starter relay leads.
For fastening, pass the plastic
locking tie through the hole in
the battery box.
A AA
C C
D
B
B B
BF FF
EE
D
A - AB - BE - E
C
F - FG - GD
KK
QRÑ
8
E
H
Ô 2 3 4
6
5
4
3
2
1
J
I
H
G
F
E
D
CBA 0 Í 9 8 Ë K 7
S
W U
V
A
0
Ú T
99
QP
PT
9 Ò
Ó
Õ Ö
Ê É
È
Ï
Ø
Ù
E
GGA
P
O
NML 9
Ð
9
Î
Û
Ý
25 mm (1.0 in)
×
Ì
35 ~ 45 mm
(1.38 ~ 1.77 in)
30 ~ 40 mm
(1.18 ~ 1.57 in)
Ü
3 - 2
INSP
ADJ
MAINTENANCE INTERVALS
NOTE:
The air filter needs more frequent service if you are riding in unusually wet or dusty areas.
17 * Steering bearingsCheck bearing assemblies for looseness.
Lubricate with lithium soap based grease every or
120 hours or 12 months (whichever comes first).√
√
18Brake and clutch
lever pivot shaftsApply lithium soap based grease lightly.
√
√
√
19Brake pedal pivot
shaftApply lithium soap based grease lightly.
√
√
√
20 Sidestand pivotCheck operation.
Apply lithium soap based grease lightly.√
√
21 * Front forkCheck operation and for oil leakage.
Replace if necessary.√
√
22 *Shock absorber
assemblyCheck operation and for oil leakage.
Replace if necessary.√
√
23 * Control cablesApply Yamaha chain and cable lube or engine oil
10W-30 thoroughly.√
√
√
24 *Throttle grip hous-
ing and cableCheck operation and free play.
Adjust the throttle cable free play if necessary.
Lubricate the throttle grip housing and cable.√
√
√
25 * Chassis fastenersCheck all chassis fitting and fasteners.
Correct if necessary.√
√
√
26Battery (TT-R90E
only)Check terminal for looseness and corrosion.
√ No. ITEMCHECKS AND
MAINTENANCE JOBSWHICH-
EVER
COMES
FIRSTINITIAL EVERY
month 1 6 12
hours 30 90 150
3
3 - 24
INSP
ADJ
BATTERY INSPECTION AND CHARGING
(TT-R90E)
WARNING
Batteries generate explosive hydrogen gas
and contain electrolyte which is made of
poisonous and highly caustic sulfuric acid.
Therefore, always follow these preventive
measures:
Wear protective eye gear when handling
or working near batteries.
Charge batteries in a well-ventilated area.
Keep batteries away from fire, sparks or
open flames (e.g., welding equipment,
lighted cigarettes).
DO NOT SMOKE when charging or han-
dling batteries.
KEEP BATTERIES AND ELECTROLYTE
OUT OF REACH OF CHILDREN.
Avoid bodily contact with electrolyte as it
can cause severe burns or permanent eye
injury.
FIRST AID IN CASE OF BODILY CONTACT:
EXTERNAL
Skin — Wash with water.
Eyes — Flush with water for 15 minutes
and get immediate medical attention.
INTERNAL
Drink large quantities of water or milk fol-
lowed with milk of magnesia, beaten egg
or vegetable oil. Get immediate medical
attention.
CAUTION:
Charging time, charging amperage and
charging voltage for an MF battery are dif-
ferent from those of conventional batteries.
The MF battery should be charged as
explained in the charging method illustra-
tions. If the battery is overcharged, the
electrolyte level will drop considerably.
Therefore, take special care when charging
the battery.
BATTERY INSPECTION AND CHARGING (TT-R90E)
3 - 25
INSP
ADJ
BATTERY INSPECTION AND CHARGING (TT-R90E)
NOTE:
Since MF batteries are sealed, it is not possi-
ble to check the charge state of the battery by
measuring the specific gravity of the electro-
lyte. Therefore, the charge of the battery has to
be checked by measuring the voltage at the
battery terminals.
1. Remove:
Seat
Rear fender
2. Disconnect:
Battery lead coupler 1
(from the battery terminals)
NOTE:
Push down on the tab a, and then remove the
battery lead coupler.
3. Remove:
Battery
1 a
4. Measure:
Battery charge
Measurement steps:
Connect a pocket tester 1 to the battery
terminals.
Tester positive probe
→ battery positive
terminal
Tester negative probe
→ battery negative
terminal
NOTE:
The charge state of an MF battery can be
checked by measuring its open-circuit volt-
age (i.e., the voltage when the positive ter-
minal is disconnected).
No charging is necessary when the open-
circuit voltage equals or exceeds 12.8 V.
1