Yamaha Wr 450 F Owners Manual

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CHASREAR SHOCK ABSORBER
2. Tighten:
Adjuster 1 
3. Adjust:
Spring length (installed) a 
* For EUROPE, AUS, NZ and ZA
NOTE:
The length of the spring (installed) changes
1.5 mm (0.06 in) per turn of the adjuster.
ACHTUNG:CAUTION:
Never attempt to turn the adjuster beyond
the maximum or minimum setting.
4. Tighten:
Locknut 1 
Rear shock absorber
1. Install:
Dust seal 1 
O-ring 2 
Collar 3 
NOTE:
Apply the molybdenum disulfide grease on
the bearing.
Apply the lithium soap base grease on the
dust seals, O-rings and collars.
Spring length (installed) a:
Standard
lengthExtent of
adjustment
246 mm (9.69 in)
* 246.5 mm (9.70 in)240.5 ~ 258.5 mm
(9.47 ~ 10.18 in)
New 
						

							5 - 67
CHASREAR SHOCK ABSORBER
2. Install:
Bush 1 
Collar 2 
Dust seal 3 
NOTE:
Apply the molybdenum disulfide grease on
the bearing.
Apply the lithium soap base grease on the
bush, collars and dust seals.
Install the dust seals with their lips facing
outward.
3. Install:
Rear shock absorber
4. Install:
Bolt (rear shock absorber-frame) 1 
Nut (rear shock absorber-frame) 2 
NOTE:
Apply the molybdenum disulfide grease on the
bolt.
5. Install:
Bolt (rear shock absorber-relay arm) 1
Nut (rear shock absorber-relay arm) 2
NOTE:
Apply the molybdenum disulfide grease on the
bolt.
T R..56 Nm (5.6 m · kg, 40 ft · lb)
T R..53 Nm (5.3 m · kg, 38 ft · lb)
6. Install:
Rear frame 1 
Bolt [rear frame (upper)] 2 
Bolt [rear frame (lower)] 3 
T R..32 Nm (3.2 m · kg, 23 ft · lb)
T R..29 Nm (2.9 m · kg, 21 ft · lb)
7. Tighten:
Screw (air filter joint) 1 
T R..3 Nm (0.3 m · kg, 2.2 ft · lb) 
						

							5 - 68
CHAS
8. Install:
Plastic band 1 
Starting circuit cut-off relay coupler 2 
Taillight coupler 3 
Locking tie 4
3
2
1
4
REAR SHOCK ABSORBER 
						

							 
6 - 1
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ELECTRICAL COMPONENTS AND WIRING DIAGRAM 
EC600000 
ELECTRICAL 
EC610000 
ELECTRICAL COMPONENTS AND WIRING DIAGRAM 
EC611000 
ELECTRICAL COMPONENTS 
1  
Headlight  
2  
“ENGINE STOP”
button  
3  
Clutch switch  
4 
Diode 
5 
Starter relay diode 
6 
TPS (throttle posi-
tion sensor) 
7 
Starter relay 
8 
Fuse 
9 
Starting circuit
cut-off relay 
0  
Taillight  
A  
Neutral switch  
B 
Starter motor  
C 
AC magneto 
D 
Rectifier/regulator 
E 
Ignition coil 
F 
Spark plug 
G 
Start switch 
H 
Lights switch 
I 
Main switch 
J 
CDI unit 
K 
Battery 
COLOR CODE 
B.......................Black
Br .....................Brown
Gy ....................Gray
L .......................Blue
O ......................Orange
R ......................Red
Sb.....................Sky blue
W......................White
Y.......................Yellow
B/L....................Black/Blue 
EC612000 
WIRING DIAGRAM
1 2345
678
90
A B
CDEFGH
I
J
K
WR
WR
R
BR/BBr
R
BR/BBr
RW
L/RL/BBB
SbL/W
WY
YW
L/YBBB
WY
RYW
R
LY
B
YLB/L
B
B
ON
OFF
10A
BB
OFF
ON
OFF
STARTSTART
R-BrL/W
BLY
YLB-LB
B
BrL/W
BrL/W
L/B-LB
YL
B
L-B
L/WSb
B/WBBB
W/RB/W
R/BGyBrL/W
ON
STOP
OB
LYSbB/L
W RBrB/W
L/BGyWR/B
B O
L/YSbL/R
R W
Y W
Y W
Y B
B
L
L L
L B
B
B
RRR/B
B Br B
B B B B
L/W
R
R
R R B
R
BrBr
L/W L/W
Br B
L/B
L/B
L/R
 
Br
R/B
L/B        L/W
B/W
W        W/RW
RO
L
Y
B/L
O
 
B
L
Y
B/LSbL/WB/W
B
L/R L/Y L/Y
B
SbSbL/W
BGy
SbBB/LYO
L
∗2
O B
L YL/W
B/L
∗1
C
HD
BI
5
9
G3 4
A 2J
EF
6 7
K8
1
0
∗
2
∗1
∗2: Except for USA
∗1: For USA
 
B/W .................. Black/White
L/B ................... Blue/Black
L/R ................... Blue/Red
L/Y ................... Blue/Yellow
L/W .................. Blue/White
R/B................... Red/Black 
						

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6 - 2 
MAP-CONTROLLED CDI UNIT
MAP-CONTROLLED CDI UNIT 
A map-controlled, CDI ignition system is used in the WR450F.
The microcomputer in the CDI unit detects the engine speed and throttle position, thus determining
the optimum ignition timing through the entire operating range. In this way, quick throttle response
can be achieved according to various riding conditions.
CDI unit
Throttle position sensor
Pickup coil AC magneto rotorIgnition coil
 
 
Function of Component 
  
Component Function
TPS 
(throttle position sensor)Detects throttle valve opening and inputs it into the computer in the 
CDI unit as a throttle opening signal.
Pickup coil Detects signal rotor revolutions and inputs them into the computer in 
the CDI unit as engine revolution signals.
CDI unit The signals of the TPS and pickup coil sensor are analyzed by the 
computer in the CDI unit, which then adjusts ignition timing for the 
operation requirements. 
 
Principal of 3-Dimensional Control 
Conventionally, ignition timing was controlled only
by engine revolutions (2-dimensional control).
However, ignition timing needs advancement also
by engine load. Thus, accurate ignition timing can
be determined by adding throttle opening to deter-
mine ignition timing (3-dimensional control). 
3-D Image Map of Ignition Timing
(different from actual characteristics)
Revolutions
Ignition timing
Throttle opening
 
 
6  
						

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6 - 3 
IGNITION SYSTEM 
EC620000 
IGNITION SYSTEM 
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. 
*1 marked: Refer to “FUSE INSPECTION” section in the CHAPTER 3.
*2 marked: Refer to “BATTERY INSPECTION AND CHARGING” section in the CHAPTER 3.
*3 marked: Only when the ignition checker is used.
NOTE:
 
 
Remove the following parts before inspection.
1) Seat
2) Fuel tank 
 
Use the following special tools in this inspection. 
Dynamic spark tester:
YM-34487
Ignition checker:
90890-06754 
Pocket tester:
YU-3112-C/90890-03112
*1 Check fuse.Replace fuse and 
check wire harness.
*2 Check battery Recharge or replace.
Spark gap test*3 Clean or replace 
spark plug.
Check entire ignition
system for connection.
(couplers, leads and 
ignition coil)Repair or replace.
Check “ENGINE STOP” 
button.Replace.
Check main switch. Replace.
Check ignition coil. Primary coil Replace.
Secondary coil Replace.
Check AC magneto. Pick-up coil Replace.
Check neutral switch. Repair or replace.
Replace CDI unit.
OK
OK
No spark
OK
OK
OK
OK
OK
OK
Spark
No good
No good
No good
No good
No good
No good
No good
No good
No good 
						

							 
6 - 4
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IGNITION SYSTEM 
SPARK GAP TEST 
1. Disconnect the ignition coil from spark
plug.
2. Remove the ignition coil cap.
3. Connect the dynamic spark tester  
1  
(ignition checker  
2 
) as shown. 
 
Ignition coil  
3 
  
 
Spark plug  
4 
  
Å 
For USA and CDN 
ı 
Except for USA and CDN 
4. Kick the kickstarter.
5. Check the ignition spark gap.
6. Start engine, and increase spark gap until
misfire occurs. (for USA and CDN only) 
Minimum spark gap:
6.0 mm (0.24 in)
Å
ı
 
COUPLERS, LEADS AND IGNITION COIL 
CONNECTION INSPECTION 
1. Check: 
 
Couplers and leads connection
Rust/dust/looseness/short-circuit  
→ 
 
Repair or replace.
Ignition coil and spark plug as they are
fitted
Push in the ignition coil until it closely 
contacts the spark plug hole in the cyl-
inder head cover.
EC625001
“ENGINE STOP” BUTTON INSPECTION
1. Inspect:
“ENGINE STOP” button conduct
No continuity while being pushed → Replace.
Continuity while being freed → Replace.
2. Inspect:
Rubber part a
Tears/damage → Replace. Tester (+) lead → Black lead 1 
Tester (–) lead → Black lead 2 
B
1B
2Tester selector 
position
PUSH IN
Ω × 1
FREE
a 
						

							6 - 5
–+ELECIGNITION SYSTEM
MAIN SWITCH INSPECTION
1. Inspect:
Main switch conduct
Continuous while the main switch is moved to
“OFF” → Replace.
Not continuous while the main switch is moved
to “ON” → Replace.
2. Inspect:
Main switch indicator light
Use 12 V battery.
Indicator light does not come on → Replace.
3. Inspect:
Rubber part a
Tears/damage → Replace. Tester (+) lead → Red lead 1 
Tester (–) lead → Brown lead 2 
R
1Br
2Tester selector 
position
ON
Ω × 1
OFF
Battery (+) lead → Red/Black lead 1 
Battery (–) lead → Black lead 2 
a
EC626002
IGNITION COIL INSPECTION
1. Remove the ignition coil cap.
2. Inspect:
Primary coil resistance
Out of specification → Replace.
Tester (+) lead → Orange lead 1 
Tester (–) lead → Black lead 2 
Primary coil 
resistanceTester selector 
position
0.08 ~ 0.10 Ω at 
20 ˚C (68 ˚F)Ω × 1 
						

							6 - 6
–+ELECIGNITION SYSTEM
3. Inspect:
Secondary coil resistance
Out of specification → Replace.
4. Inspect:
Sealed portion of ignition coil a
Spark plug terminal pin b
Threaded portion of spark plug c
Wear → Replace.
AC MAGNETO INSPECTION
1. Inspect:
Pick-up coil resistance
Out of specification → Replace. Tester (+) lead → Orange lead 1 
Tester (–) lead → Spark plug terminal 2 
Secondary coil 
resistanceTester selector 
position
4.6 ~ 6.8 kΩ at 
20 ˚C (68 ˚F)kΩ × 1
Tester (+) lead → Red lead 1 
Tester (–) lead → White lead 2 
Pick-up coil 
resistanceTester selector 
position
248 ~ 372 Ω at 
20 ˚C (68 ˚F)Ω × 100
RW
12
NEUTRAL SWITCH INSPECTION
1. Inspect:
Neutral switch conduct
No continuity while in neutral → Replace.
Continuity while in gear → Replace.
EC628000
CDI UNIT INSPECTION
Check all electrical components. If no fault is
found, replace the CDI unit. Then check the
electrical components again.Tester (+) lead → Sky blue lead 1 
Tester (–) lead → Ground 2
Sb
1GroundTester selec-
tor position
NEUTRALΩ × 1IN GEAR
–+ Ω×1
1
2L/W Sb 
						

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ELECTRIC STARTING SYSTEM
STARTING CIRCUIT CUT-OFF SYSTEM 
OPERATION
If the main switch is set to “ON”, the starter
motor can only operate if at least one of the
following conditions is met: 
The transmission is in neutral (the neutral
switch is closed). 
The clutch lever is pulled to the handlebar
(the clutch switch is closed).
The starting circuit cut-off relay prevents the
starter motor from operating when neither of
these conditions has been met. In this
instance, the starting circuit cut-off relay is
open so current cannot reach the starter
motor. When at least one of the above condi-
tions has been met the starting circuit cut-off
relay is closed and the engine can be started
by pressing the start switch.
WHEN THE TRANSMISSION IS
IN NEUTRAL
WHEN THE CLUTCH LEVER IS
PULLED TO THE HANDLEBAR
1Battery
2Main fuse 
3Main switch 
4Starting circuit cut-off relay 
5Start switch
6Diode
7Clutch switch 
8Neutral switch 
9Starter relay 
0Starter motor
12
M
3
4
5
8 76 9
0
ELECTRIC STARTING SYSTEM