ignition YAMAHA WR 450F 2007 User Guide

3 - 57
INSP
ADJ
REPLACING THE HEADLIGHT BULBS
3. Replace:
Blown fuse
WARNING
Never use a fuse with an amperage rating
other than that specified. Improvising or
using a fuse with the wrong amperage rat-
ing may cause extensive damage to the
electrical system, cause the starting and
ignition systems to malfunction and could
possibly cause a fire.
4. Install:
Fuse cover
Seat Replacement steps:
Set the main switch to “OFF”.
Install a new fuse of the correct amperage.
Set on the switches to verify if the electri-
cal circuit is operational.
If the fuse immediately blows again, check
the electrical circuit.
ItemsAmperage
ratingQ’ty
Main fuse 10 A 1
REPLACING THE HEADLIGHT BULBS
1. Remove:
Headlight
Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section in the CHAPTER 4.
2. Remove:
Headlight bulb holder cover 1
3. Remove:
Headlight bulb holder 1
NOTE:
Remove the headlight bulb holder by pushing
it in and turning it counterclockwise.

4 - 90
ENGENGINE REMOVAL
Extent of removal:
1 Engine removal
Extent of removal Order Part name Q’ty Remarks
Cylinder head breather hose Refer to “CAMSHAFTS” section.
Ignition coil
Disconnect the AC magneto lead.
Disconnect the starter motor
lead.Refer to “ELECTRIC STARTING SYS-
TEM” section in the CHAPTER 6.
Negative battery lead Disconnect at the starter motor side.
1 Engine guard 1
2 Neutral switch 1
3 Chain cover 1
4 Nut (drive sprocket) 1
Refer to “REMOVAL POINTS”. 5 Lock washer 1
6 Drive sprocket 1
7Clip 1
8 Bolt (brake pedal) 1
9 Brake pedal 1
1

6 - 1
–+ELECELECTRICAL COMPONENTS AND WIRING DIAGRAM
EC600000
ELECTRICAL
EC610000
ELECTRICAL COMPONENTS AND WIRING DIAGRAM
EC611000
ELECTRICAL COMPONENTS
1Headlight
2Multi-function display
3“ENGINE STOP” but-
ton
4Clutch switch
5Diode
6Starter relay diode
7TPS (throttle posi-
tion sensor)
8Starter relay
9Fuse
0Starting circuit cut-off
relayACDI unit
BTaillight
CNeutral switch
DStarter motor
EAC magneto
FRectifier/regulator
GIgnition coil
HSpark plug
IStart switch
JMain switch
KSpeed sensor
LBatteryCOLOR CODE
B ...................... Black
Br ..................... Brown
Ch .................... Chocolate
Dg .................... Dark green
G ...................... Green
Gy .................... Gray
L....................... Blue
O ...................... Orange
R ...................... Red
Sb .................... Sky blue
EC612000
WIRING DIAGRAM
W ..................... White
Y ...................... Yellow
B/L ................... Black/Blue
B/W .................. Black/White
L/B ................... Blue/Black
L/R ................... Blue/Red
L/Y ................... Blue/Yellow
L/W .................. Blue/White
R/B................... Red/Black
R/W.................. Red/White

–+ELEC
6 - 2
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:
90890-06754Pocket 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 - 3
–+ELECIGNITION 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 (igni-
tion checker 2) as shown.
•Ignition coil 3
•Spark plug 4
ÈFor USA and CDN
ÉExcept 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)
È
É
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 fit-
ted
Push in the ignition coil until it closely
contacts the spark plug hole in the cylin-
der 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
1 B
2 Tester selec-
tor position
PUSH IN
Ω
×
×× × 1
FREE
a

6 - 4
–+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
1 Br
2 Tester selec-
tor 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 - 5
–+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.
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
→ Orange lead
1
Tester (–) lead
→ Spark plug terminal
2
Secondary coil
resistanceTester selector
position
4.6 ~ 6.8 k
Ω at
20 °C (68 °F)k
Ω
× 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
Tester (+) lead
→ Sky blue lead
1
Tester (–) lead
→ Ground
2
Sb
1 Ground 2
Tester selec-
tor position
NEUTRAL
Ω
×
×× × 1
IN GEAR

–+ELEC
6 - 18
TPS (THROTTLE POSITION SENSOR) SYSTEM
EC690000
TPS (THROTTLE POSITION SENSOR) SYSTEM
INSPECTION STEPS
If the TPS will not operate, use the following inspection steps.
NOTE:
Use the following special tools in this inspection.
Pocket tester:
YU-3112-C/90890-03112
Check entire ignition
system for connection.Repair or replace.
Check TPS. TPS coil Replace.
Check CDI unit.TPS input
voltageReplace.
OK
OK
No good
No good
No good