engine oil YAMAHA YZ250F 2007 Workshop Manual

6 - 1
–+ELECELECTRICAL COMPONENTS AND WIRING DIAGRAM
EC600000
ELECTRICAL
EC610000
ELECTRICAL COMPONENTS AND WIRING DIAGRAM
EC611000
ELECTRICAL COMPONENTS
1Engine stop switch
2Throttle position sensor
3Neutral switch
4CDI magneto
5Ignition coil
6Spark plug
7CDI unitCOLOR CODE
B ...................... Black
Br .................... Brown
G ..................... Green
L ...................... Blue
O ..................... Orange
P ...................... Pink
R ..................... Red
Sb.................... Sky blue
EC612000
WIRING DIAGRAM
71
5
62
3
4
B/WB/W
B/L
B/Y
SbSb
G/B
LYLY
P
B
B
B
B
G
O
WR
P
GW
R PP
B Br W
W
B/YGBr
G RR
OB Sb Sb Y
Y
WY
W
GG
B
PP
Br BrR R
OL
B SbY LL
B/L B/WB/W G/B
B B
B/L L Sb
B/L
G/B
G/BB/Y
B/Y
B/W
O B/W
BrBr
W ..................... White
Y ...................... Yellow
B/L ................... Black/Blue
B/W .................. Black/White
B/Y ................... Black/Yellow
G/B................... Green/Black
L/W .................. Blue/White
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.
*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
Spark gap test*Clean or replace
spark plug.
Check entire ignition
system for connection.
(couplers, leads and
ignition coil)Repair or replace.
Check engine stop switch. Replace.
Check ignition coil. Primary coil Replace.
Secondary coil Replace.
Check CDI magneto. Pickup coil Replace.
Charging coil Replace.
Check neutral switch. Repair or replace.
Replace CDI unit.
No spark
OK
OK
OK
OK
OK
Spark
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 crank.
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.
ENGINE STOP SWITCH INSPECTION
1. Inspect:
•Engine stop switch conduct
No continuous while being pushed → Replace.
Continuous while being freed → Replace. Tester (+) lead
→ Black/White lead
1
Tester (–) lead
→ Black lead
2
B/W
1 B
2 Tester selec-
tor position
PUSH IN
Ω
× 1
FREE1 2
B/W B

6 - 7
–+ELECTHROTTLE POSITION SENSOR SYSTEM
HANDLING NOTE
CAUTION:
Do not loosen the screws (throttle position
sensor)
1 except when changing the throt-
tle 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.
THROTTLE POSITION SENSOR COIL
INSPECTION
1. Inspect:
•Throttle position sensor coil resistance
Out of specification → Replace.
Tester (+) lead
→ Blue lead
1
Tester (–) lead
→ Black lead
2
Throttle posi-
tion sensor coil
resistanceTester selector
position
4 ~ 6 kΩ at
20 °C (68 °F)kΩ × 1
2. Loosen:
•Throttle stop screw 1
NOTE:
Turn out the throttle stop screw until the throt-
tle shaft is in the full close position.