2007 YAMAHA WR 450F engine oil

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 - 17
–+ELECCHARGING SYSTEM
EC624000
COUPLERS AND LEADS CONNECTION
INSPECTION
1. Check:
•Couplers and leads connection
Rust/dust/looseness/short-circuit →
Repair or replace.
CHARGING VOLTAGE INSPECTION
1. Start the engine.
2. Inspect:
•Charging voltage
Out of specification → If no failure is
found in checking the source coil resis-
tance, replace the rectifier/regulator.
Tester (+) lead
→ Red lead
1
Tester (–) lead
→ Black lead
2
Charging
voltageTester selector
position
14.0 ~ 15.0 V at
5,000 r/minDCV-20
R
BW Y1
2
3. Inspect:
•Charging coil resistance
Out of specification → Replace.
Tester (+) lead
→ White lead
1
Tester (–) lead
→ Ground
2
Charging coil
resistanceTester selector
position
0.288 ~ 0.432
Ω
at 20 °C (68 °F)Ω
× 1

6 - 19
–+ELECTPS (THROTTLE POSITION SENSOR) SYSTEM
HANDLING NOTE
CAUTION:
Do not loosen the screw {TPS (throttle
position sensor)}
1 except when changing
the TPS (throttle position sensor) due to
failure because it will cause a drop in
engine performance.
1
EC624000
COUPLERS AND LEADS CONNECTION
INSPECTION
1. Check:
•Couplers and leads connection
Rust/dust/looseness/short-circuit →
Repair or replace.
TPS COIL INSPECTION
1. Inspect:
•TPS coil resistance
Out of specification → Replace.
2. Loosen:
•Throttle stop screw 1
NOTE:
Turn out the throttle stop screw until the throt-
tle shaft is in the full close position.Tester (+) lead
→ Blue lead
1
Tester (–) lead
→ Black lead
2
TPS coil
resistanceTester selector
position
4 ~ 6 kΩ at
20 °C (68 °F)kΩ × 1