2007 YAMAHA YZ250F oil

5 - 57
CHASSWINGARM
Connecting rod
1. Inspect:
•Bearing 1
•Collar 2
Free play exists/unsmooth revolution/rust
→ Replace bearing and collar as a set.
2. Inspect:
•Oil seal 3
Damage → Replace.
EC575000
ASSEMBLY AND INSTALLATION
Bearing and oil seal
1. Install:
•Bearing 1
•Oil seal 2
To swingarm.
NOTE:
•Apply the molybdenum disulfide grease on
the bearing when installing.
•Install the bearing by pressing it on the side
having the manufacture’s marks or numbers.
•First install the outer and then the inner bear-
ings to a specified depth from inside.
Installed depth of bearings:
Outer
a: Zero mm (Zero in)
Inner
b: 6.5 mm (0.26 in)
2. Install:
•Bearing 1
•Washer 2
•Oil seal 3
To relay arm.
NOTE:
•Apply the molybdenum disulfide grease on
the bearing when installing.
•Install the bearing by pressing it on the side
having the manufacture’s marks or numbers.
•Apply the molybdenum disulfide grease on
the washer.
Installed depth of bearings
a:
Zero mm (Zero in)

5 - 58
CHASSWINGARM
3. Install:
•Bearing 1
•Oil seal 2
To connecting rod.
NOTE:
•Apply the molybdenum disulfide grease on
the bearing when installing.
•Install the bearing by pressing it on the side
having the manufacture’s marks or numbers.
Installed depth of bearings
a:
Zero mm (Zero in)
Swingarm
1. Install:
•Bushing 1
•Thrust bearing 2
•Oil seal 3
•Collar 4
To swingarm 5.
NOTE:
Apply the molybdenum disulfide grease on the
bushings, thrust bearings, oil seal lips and con-
tact surfaces of the collar and thrust bearing.
2. Install:
•Collar 1
•Washer 2
To relay arm 3.
NOTE:
Apply the molybdenum disulfide grease on the
collars and oil seal lips.

5 - 59
CHASSWINGARM
3. Install:
•Collar 1
To connecting rod 2.
NOTE:
Apply the molybdenum disulfide grease on the
collar and oil seal lips.
4. Install:
•Connecting rod 1
•Bolt (connecting rod) 2
•Washer 3
•Nut (connecting rod) 4
To relay arm 5.
NOTE:
Apply the molybdenum disulfide grease on the
bolt.
5. Install:
•Relay arm 1
•Bolt (relay arm) 2
•Washer 3
•Nut (relay arm) 4
To swingarm.
NOTE:
•Apply the molybdenum disulfide grease on
the bolt circumference and threaded portion.
•Do not tighten the nut yet.
6. Install:
•Swingarm 1
•Pivot shaft 2
NOTE:
•Apply the molybdenum disulfide grease on
the pivot shaft.
•Insert the pivot shaft from right side.
7. Check:
•Swingarm side play a
Free play exists → Replace thrust bear-
ing.
•Swingarm up and down movement b
Unsmooth movement/binding/rough
spots → Grease or replace bearings,
bushings and collars.
T R..80 Nm (8.0 m · kg, 58 ft · lb)
T R..85 Nm (8.5 m · kg, 61 ft · lb)

5 - 64
CHAS
HANDLING NOTE
WARNING
This rear shock absorber is provided with a
separate type tank filled with high-pressure
nitrogen gas. To prevent the danger of
explosion, read and understand the follow-
ing information before handling the shock
absorber.
The manufacturer can not be held respon-
sible for property damage or personal
injury that may result from improper han-
dling.
1. Never tamper or attempt to disassemble
the cylinder or the tank.
2. Never throw the rear shock absorber
into an open flame or other high heat.
The rear shock absorber may explode as
a result of nitrogen gas expansion and/
or damage to the hose.
3. Be careful not to damage any part of the
gas tank. A damaged gas tank will impair
the damping performance or cause a
malfunction.
4. Take care not to scratch the contact sur-
face of the piston rod with the cylinder;
or oil could leak out.
5. Never attempt to remove the plug at the
bottom of the nitrogen gas tank. It is
very dangerous to remove the plug.
6. When scrapping the rear shock
absorber, follow the instructions on dis-
posal.
NOTES ON DISPOSAL (YAMAHA DEALERS
ONLY)
Before disposing the rear shock absorber, be
sure to extract the nitrogen gas from valve 1.
Wear eye protection to prevent eye damage
from escaping gas and/or metal chips.
WARNING
To dispose of a damaged or worn-out rear
shock absorber, take the unit to your
Yamaha dealer for this disposal procedure.
REAR SHOCK ABSORBER

5 - 65
CHAS
EC583000
REMOVAL POINTS
EC583320
Bearing
1. Remove:
•Stopper ring (upper bearing) 1
NOTE:
Press in the bearing while pressing its outer
race and remove the stopper ring.
2. Remove:
•Upper bearing 1
NOTE:
Remove the bearing by pressing its outer race.
3. Remove:
•Lower bearing 1
NOTE:
Remove the bearing by pressing its outer race.
EC584000
INSPECTION
Rear shock absorber
1. Inspect:
•Damper rod 1
Bends/damage → Replace rear shock
absorber assembly.
•Shock absorber 2
Oil leaks → Replace rear shock absorber
assembly.
Gas leaks → Replace rear shock
absorber assembly.
•Spring 3
Damage → Replace spring.
Fatigue → Replace spring.
Move spring up and down.
•Spring guide 4
Wear/damage → Replace spring guide.
•Spring seat 5
Cracks/damage → Replace.
•Bearing 6
Free play exists/unsmooth revolution/rust
→ Replace.
REAR SHOCK ABSORBER

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