2000 YAMAHA TTR90 oil

5 - 8
CHASFRONT FORK
REMOVAL POINTS
Inner tube
1. Remove:
lBolt (damper rod)
NOTE:
While holding the damper rod with the damper
rod holder 1 and T-handle 2, loosen the bolt
(damper rod).
Damper rod holder:
YM-01300/90890-01294
T-handle:
YM-01326/90890-01326
EC555000
ASSEMBLY AND INSTALLATION
1. Install:
lOil seal 1
NOTE:
Press the oil seal into the outer tube with fork
seal driver weight 2 and fork seal driver
attachment 3.
2. Fill:
lFork oil
Fork seal driver weight:
YM-33963/YM-01442/90890-01184
Fork seal driver attachment:
YM-1369/90890-01186
Oil quantity:
64 cm3 (2.26 Imp oz, 2.16 US oz)
Recommended oil:
Fork oil 15W or equivalent
3. After filling up, slowly pump the fork up
and down to distribute the fork oil.

6 - 1
–+ELEC

ELECTRICAL COMPONENTS AND WIRING DIAGRAM
EC600000
ELECTRICAL
EC610000
ELECTRICAL COMPONENTS AND WIRING DIAGRAM
EC611000
ELECTRICAL COMPONENTS
1
CDI magneto
2
CDI unit
3
Ignition coil
4
Spark plug
5
“ENGINE STOP” switch
6
Thermo switch
7
Carburetor heater
8
Rectifier/regulator
COLOR 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
6

–+ELEC

6 - 2
IGNITION SYSTEM
EC620000
IGNITION SYSTEM
EC621001
INSPECTION STEPS
Use the following steps for checking the possibility of the malfunctioning engine being attributable to
ignition system failure and for checking the spark plug which will not spark.
NOTE:

l
Remove the following parts before inspection.
1) Seat
2) Fuel tank
l
Use the following special tools in this inspection.
Spark gap testClean or replace
spark plug.
Check entire ignition
system for connection.Repair or replace.
Check “ENGINE STOP”
switch.Replace.
Check ignition coil. Primary coil Replace.
Secondary coilReplace.
Check CDI magneto. Pickup coil Replace.
Source coil Replace.
Replace CDI unit.
Dynamic spark tester:
YM-34487
Ignition checker:
90890-06754
Pocket tester:
YU-03112/90890-03112
No Spark
OK
OK
OK
OK
Spark
No good
No good
No good
No good
No good
No good

6 - 4
–+ELEC

IGNITION SYSTEM
EC626002
IGNITION COIL INSPECTION
1. Inspect:
l
Primary coil resistance
Out of specification
®
Replace.
Tester (+) lead
®
Orange lead
1

Tester (–) lead
®
Black lead
2

Primary coil
resistanceTester selector
position
0.18 ~ 0.28
W
at
20 ˚C (68 ˚F)
W

´
1
2. Inspect:
l
Secondary coil resistance
Out of specification
®
Replace.
NOTE:

When inspecting the secondary coil resis-
tance, remove the spark plug cap.
EC627011
CDI MAGNETO INSPECTION
1. Inspect:
lPickup coil resistance
Out of specification ® Replace. Tester (+) lead ® Spark plug lead 1
Tester (–) lead ® Orange lead 2
Secondary coil
resistanceTester selector
position
6.3 ~ 9.5 kW at
20 ˚C (68 ˚F)kW ´ 1
Tester (+) lead ® Red lead 1
Tester (–) lead ® White lead 2
Pickup coil
resistanceTester selector
position
248 ~ 372 W at
20 ˚C (68 ˚F)W ´ 100

6 - 5
–+ELECIGNITION SYSTEM
2. Inspect:
lSource coil resistance
Out of specification ® Replace.
Tester (+) lead ® Brown lead 1
Tester (–) lead ® Green lead 2
Source coil
resistanceTester selector
position
688 ~ 1,032 W
at 20 ˚C (68 ˚F)W ´ 100

–+ELEC
6 - 6
CARBURETOR HEATING SYSTEM
CARBURETOR HEATING SYSTEM
INSPECTION STEPS
Use the following steps for checking the possibility of the malfunctioning carburetor heating system.
NOTE:
lRemove the following parts before inspection.
1) Seat
2) Fuel tank
lUse the following special tools in this inspection.
Check entire carburetor
heating system for connec-
tion.Repair or replace.
Check thermo switch. Replace.
Check carburetor heater. Replace.
Check CDI magneto. Source coil Replace.
Replace rectifier/regulator.
Pocket tester:
YU-03112/90890-03112
OK
OK
OK
No good
No good
No good
No good
OK

6 - 7
–+ELECCARBURETOR HEATING SYSTEM
EC624000
COUPLERS AND LEADS CONNECTION
INSPECTION
1. Check:
lCouplers and leads connection
Rust/dust/looseness/short-circuit ®
Repair or replace.
CDI MAGNETO INSPECTION
1. Inspect:
lSource coil resistance
Refer to “IGNITION SYSTEM” section.
THERMO SWITCH INSPECTION
1. Inspect:
lThermo switch operation
Faulty operation ® Replace.
Inspection steps:
lRemove the thermo switch.
lConnect the pocket tester to the thermo
switch coupler as shown.
Tester (+) lead ® black 1
Tester (–) lead ® black 2
lImmerse the thermo switch in a container
filled with water 3.
lPlace a thermometer 4 in the water.
lSlowly heat the water, and then let it cool to
the specified temperature as indicated in
the table.
lCheck the thermo switch for continuity at
the temperatures indicated in the table.