2012 YAMAHA YZ250F Owners Manual

3-23
CHASSIS
LUBRICATION
To ensure smooth operation of all
components, lubricate your machine
during setup, after break-in, and after
every race.
1. All control cable
2. Clutch lever pivot
3. Shift pedal pivot
4. Footrest pivot
5. Throttle-to-handlebar contact
6. Drive chain
7. Tube guide cable winding por-
tion
8. Throttle cable end
9. Clutch cable end
10. Hot starter cable endA. Use Yamaha cable lube or
equivalent on these areas.
B. Use SAE 10W-40 motor oil or
suitable chain lubricants.
C. Lubricate the following areas
with high quality, lightweight lith-
ium-soap base grease.
Wipe off any excess grease, and
avoid getting grease on the brake
discs.

3-24
ELECTRICAL
ELECTRICAL
CHECKING THE SPARK PLUG
1. Remove:
• Spark plug
2. Inspect:
• Electrode "1"
Wear/damage→Replace.
• Insulator color "2"
Normal condition is a medium to
light tan color.
Distinctly different color→Check
the engine condition.
When the engine runs for many hours
at low speeds, the spark plug insula-
tor will become sooty, even if the en-
gine and carburetor are in good
operating condition.
3. Measure:
• Plug gap "a"
Use a wire gauge or thickness
gauge.
Out of specification→Regap.
4. Clean the plug with a spark plug
cleaner if necessary.
5. Tighten:
• Spark plug
• Before installing a spark plug, clean
the gasket surface and plug sur-
face.
• Finger-tighten "a" the spark plug
before torquing to specification "b".
CHECKING THE IGNITION TIMING
1. Remove:
• Timing mark accessing screw "1"
2. Attach:
• Timing light
• Digital tachometer
To the ignition coil lead (orange
lead"1").
3. Adjust:
• Engine idling speed
Refer to "ADJUSTING THE EN-
GINE IDLING SPEED" section.
4. Check:
• Ignition timing
Visually check the stationary
pointer "a" is within the firing
range "b" on the rotor.
Incorrect firing range→Check ro-
tor and pickup assembly.
5. Install:
• Timing mark accessing screw Spark plug gap:
0.7–0.8 mm
(0.028–0.031 in)
Spark plug:
13 Nm (1.3 m•kg, 9.4
ft•lb)
Timing light:
YM-33277-A/90890-
03141

4-1
SEAT, FUEL TANK AND SIDE COVERS
ENGINE
This section is intended for those who have basic knowledge and skill concerning the servicing of Yamaha motorcycles
(e.g., Yamaha dealers, service engineers, etc.) Those who have little knowledge and skill concerning servicing are request-
ed not to undertake inspection, adjustment, disassembly, or reassembly only by reference to this manual. It may lead to
servicing trouble and mechanical damage.
SEAT, FUEL TANK AND SIDE COVERS
REMOVING THE SEAT, FUEL TANK AND SIDE COVERS
Order Part name Q'ty Remarks
Turn the fuel cock to "OFF".
Disconnect the fuel hose.
1Seat 1
2 Air scoop (left and right) 2
3 Bolt (fuel tank) 1
4 Fitting band 1
5 Fuel tank 1
6 Left side cover 1 Refer to removal section.
7 Right side cover 1 Refer to removal section.
8 Number plate 1 Refer to removal section.
4

4-2
SEAT, FUEL TANK AND SIDE COVERS
REMOVING THE SIDE COVER
1. Remove:• Bolt (side cover)
• Left side cover "1"
• Right side cover "2"
Draw the side cover downward to re-
move it because its claws "a" are in-
serted in the air filter case.
REMOVING THE NUMBER PLATE
1. Remove:• Bolt (number plate)
• Number plate "1"
• The projection "a" is inserted into the band of the number plate. Pull
the band off the projection before
removal.
• Remove the hot starter cable "2" and clutch cable "3" from the cable
guide "b" on the number plate.
• The projection "c" on the lower bracket is inserted into the number
plate. Remove the number plate by
pulling it off the projection.

4-3
EXHAUST PIPE AND SILENCER
EXHAUST PIPE AND SILENCER
REMOVING THE EXHAUST PIPE AND SILENCER
Order Part name Q'ty Remarks
Right side coverRefer to "SEAT, FUEL TANK AND SIDE
COVERS" section.
1 Bolt (silencer clamp) 1 Only loosening.
2 Bolt [silencer (front)] 1
3 Bolt [silencer (rear)] 1
4 Silencer 1
5 Silencer clamp 1
6 Nut (exhaust pipe) 2
7 Exhaust pipe 1
8 Gasket 2

4-4
EXHAUST PIPE AND SILENCER
DISASSEMBLING THE SILENCEROrder Part name Q'ty Remarks A. For USA and CDN
1Rivet 16
2 Inner pipe 1
3 Silencer body 1
4 Fiber 1 1
5 Fiber 2 1
6 Fiber 3 2
7 Silencer end cap 1
8 Fiber 4 3
9 Fiber 5 2
10 Fiber 6 1
70 mm
(2.8 in)
100 mm (3.9 in)
83 mm
(3.3 in)
116 mm (4.6 in)
88 mm
(3.5 in)

4-5
EXHAUST PIPE AND SILENCER
CHECKING THE SILENCER AND
EXHAUST PIPE
1. Inspect:
• Gasket "1"
Damage→Replace.
CHANGING THE SILENCER FIBER
For USA and CDN
1. Remove:
• Rivet "1"
• Inner pipe "2"
• Silencer end cap "3"
Take care not to damage the rivet
fitting holes (ø4.9 mm) "a" in re-
moval.
Pull out the inner pipe while lightly
tapping the stay "b" on the silencer
using a soft hammer.
2. Replace:
• Fiber "1"
• Fiber "2"
• Fiber "3"
Install the fiber 2 to the inner pipe.
Then, after wrapping the fiber 1, as is
vinyl packaged, around fiber 2, se-
cure them using the tape "a".
3. Replace:
• Fiber (silencer end cap)"1"
The edges of the holes "b" in the
partition plate may cause an injury,
so take care not to directly touch it.
• Make cut "a" as shown using scis-
sors and the like.
• Using a stick or the like, stuff the fi-
ber in order of increasing size into
the end cap of the silencer through
hole "b" in the partition plate.
4. Install:
• Inner pipe "1"
• Rivet (front) "2"
• Apply heat resistant sealant along
the plate edge "a" on the inside of
the silencer and also along the si-
lencer edge "b" as shown.
• Take care not to allow the fiber out
of place when installing the inner
pipe.
5. Install:
• Silencer end cap "1"
• Rivet (rear) "2"
Apply heat resistant sealant along the
plate edge "a" on the inside of the si-
lencer and also along the silencer
edge "b" as shown.
Except for USA and CDN
1. Remove:
• Rivet (front) "1"
• Inner pipe "2"
Take care not to damage the rivet
fitting holes (ø4.9 mm) "a" in re-
moval.
Pull out the inner pipe while lightly
tapping the stay "b" on the silencer
using a soft hammer.
2. Replace:
• Fiber "1"
• Fiber "2"
• Fiber "3"
Install the fiber 2 to the inner pipe.
Then, after wrapping the fiber 1, as is
vinyl packaged, around fiber 2, se-
cure them using the tape "a".

4-6
EXHAUST PIPE AND SILENCER
3. Install:
• Inner pipe "1"
• Rivet (front) "2"
• Apply heat resistant sealant along
the plate edge "a" on the inside of
the silencer and also along the si-
lencer edge "b" as shown.
• Take care not to allow the fiber out
of place when installing the inner
pipe.
INSTALLING THE SILENCER AND
EXHAUST PIPE
1. Install:
• Gasket
• Exhaust pipe "1"
• Nut (exhaust pipe) "2"
First temporarily tighten both nuts to
13 Nm (1.3 m•kg, 9.4 ft•lb). Then re-
tighten the same nut to 20 Nm (2.0
m•kg, 14 ft•lb).
2. Install:
• Silencer clamp "1"
• Gasket "2"
• Silencer "3"
• Washer "4"
• Bolt (silencer) "5"
• Install the gasket with its meshed
area "a" toward the exhaust pipe
side.
• The gasket should be installed ac-
cording to the dimension shown.
Nut (exhaust pipe):
20 Nm (2.0 m•kg, 14
ft•lb)
Silencer clamp:
14 Nm (1.4 m•kg, 10
ft•lb)
Bolt (silencer):
30 Nm (3.0 m•kg, 22
ft•lb)
New