2010 YAMAHA YZ250F fuel cap

FOREWORD
INTRODUCTION
Congratulations on your purchase of
a Yamaha YZ series. This model is
the culmination of Yamaha's vast ex-
perience in the production of paceset-
ting racing machines. It represents
the highest grade of craftsmanship
and reliability that have made Yama-
ha a leader.
This manual explains operation, in-
spection, basic maintenance and tun-
ing of your machine. If you have any
questions about this manual or your
machine, please contact your Yama-
ha dealer.
Yamaha continually seeks advance-
ments in product design and quality.
Therefore, while this manual contains
the most current product information
available at the time of printing, there
may be minor discrepancies between
your machine and this manual. If you
have any questions concerning this
manual, please consult your Yamaha
dealer.
PLEASE READ THIS MANUAL
CAREFULLY AND COMPLETELY
BEFORE OPERATING THIS MA-
CHINE. DO NOT ATTEMPT TO OP-
ERATE THIS MACHINE UNTIL YOU
HAVE ATTAINED A SATISFACTO-
RY KNOWLEDGE OF ITS CON-
TROLS AND OPERATING
FEATURES AND UNTIL YOU HAVE
BEEN TRAINED IN SAFE AND
PROPER RIDING TECHNIQUES.
REGULAR INSPECTIONS AND
CAREFUL MAINTENANCE,
ALONG WITH GOOD RIDING
SKILLS, WILL ENSURE THAT YOU
SAFETY ENJOY THE CAPABILI-
TIES AND THE RELIABILITY OF
THIS MACHINE.
IMPORTANT MANUAL
INFORMATION
Particularly important information is
distinguished in this manual by the
following notations.
This is the safety alert symbol. It is
used to alert you to potential per-
sonal injury hazards. Obey all safe-
ty messages that follow this
symbol to avoid possible injury or
death. A WARNING indicates a hazardous
situation which, if not avoided,
could result in death or serious in-
jury.
A NOTICE indicates special pre-
cautions that must be taken to
avoid damage to the vehicle or oth-
er property.
A TIP provides key information to
make procedures easier or clearer.
SAFETY INFORMATION
THIS MACHINE IS DESIGNED
STRICTLY FOR COMPETITION
USE, ONLY ON A CLOSED
COURSE. It is illegal for this machine
to be operated on any public street,
road, or highway. Off-road use on
public lands may also be illegal.
Please check local regulations before
riding.
• THIS MACHINE IS TO BE OPER-
ATED BY AN EXPERIENCED RID-
ER ONLY.
Do not attempt to operate this ma-
chine at maximum power until you
are totally familiar with its character-
istics.
• THIS MACHINE IS DESIGNED TO
BE RIDDEN BY THE OPERATOR
ONLY.
Do not carry passengers on this
machine.
• ALWAYS WEAR PROTECTIVE APPAREL.
When operating this machine, al-
ways wear an approved helmet with
goggles or a face shield. Also wear
heavy boots, gloves, and protective
clothing. Always wear proper fitting
clothing that will not be caught in
any of the moving parts or controls
of the machine.
• ALWAYS MAINTAIN YOUR MA- CHINE IN PROPER WORKING
ORDER.
For safety and reliability, the ma-
chine must be properly maintained.
Always perform the pre-operation
checks indicated in this manual.
Correcting a mechanical problem
before you ride may prevent an ac-
cident.
• GASOLINE IS HIGHLY FLAMMA-
BLE.
Always turn off the engine while re-
fueling. Take care to not spill any
gasoline on the engine or exhaust
system. Never refuel in the vicinity of an open flame, or while smoking.
• GASOLINE CAN CAUSE INJURY. If you should swallow some gaso-
line, inhale excess gasoline vapors,
or allow any gasoline to get into
your eyes, contact a doctor immedi-
ately. If any gasoline spills onto
your skin or clothing, immediately
wash skin areas with soap and wa-
ter, and change your clothes.
• ONLY OPERATE THE MACHINE IN AN AREA WITH ADEQUATE
VENTILATION.
Never start the engine or let it run
for any length of time in an enclosed
area. Exhaust fumes are poison-
ous. These fumes contain carbon
monoxide, which by itself is odor-
less and colorless. Carbon monox-
ide is a dangerous gas which can
cause unconsciousness or can be
lethal.
• PARK THE MACHINE CAREFUL- LY; TURN OFF THE ENGINE.
Always turn off the engine if you are
going to leave the machine. Do not
park the machine on a slope or soft
ground as it may fall over.
• THE ENGINE, EXHAUST PIPE, MUFFLER, AND OIL TANK WILL
BE VERY HOT AFTER THE EN-
GINE HAS BEEN RUN.
Be careful not to touch them or to
allow any clothing item to contact
them during inspection or repair.
• PROPERLY SECURE THE MA- CHINE BEFORE TRANSPORTING
IT.
When transporting the machine in
another vehicle, always be sure it is
properly secured and in an upright
position and that the fuel cock is in
the "OFF" position. Otherwise, fuel
may leak out of the carburetor or
fuel tank.
F.I.M. MACHINE WEIGHTS
Weights of machines without fuel
The minimum weights for motocross
machines are:
for the class 125 cc:
minimum 88 kg (194 lb)
for the class 250 cc:
minimum 98 kg (216 lb)
for the class 500 cc:
minimum 102 kg (225 lb)
In modifying your machine (e.g., for
weight reduction), take note of the
above limits of weight.

1-5
DESCRIPTION
DESCRIPTION
• The machine you have purchased may differ slightly from those shown in the following.
• Designs and specifications are subject to change without notice.
1. Clutch lever
2. Hot starter lever
3. Front brake lever
4. Throttle grip
5. Radiator cap
6. Fuel tank cap
7. Engine stop switch
8. Kickstarter crank
9. Fuel tank
10. Radiator
11. Coolant drain bolt
12. Rear brake pedal
13. Valve joint14. Fuel cock
15. Cold starter knob
16. Air filter
17. Drive chain
18. Shift pedal
19. Oil level check window
20. Front fork

2-1
GENERAL SPECIFICATIONS
SPECIFICATIONS
GENERAL SPECIFICATIONS
Model name:YZ250FZ (USA, CDN, AUS, NZ)
YZ250F (EUROPE, ZA)
Model code number: 17D5 (USA,CDN)
17D6 (EUROPE)
17D8 (AUS, NZ, ZA)
Dimensions: USA, CDN EUROPE AUS, NZ, ZA
Overall length 2,159 mm (85.00
in) 2,168 mm (85.35
in)2,166 mm (85.28
in)
Overall width 825 mm (32.48 in)←←
Overall height 1,303 mm (51.30
in) 1,304 mm (51.34
in)←
Seat height 988 mm (38.90 in) 991 mm (39.02 in) 990 mm (38.98 in)
Wheelbase 1,466 mm (57.72
in) 1,473 mm (57.99
in)←
Minimum ground clearance 375 mm (14.76 in) 377 mm (14.84 in) 376 mm (14.80 in)
Weight: With oil and fuel 102.0 kg (224.9 lb)
Engine: Engine type Liquid cooled 4-stroke, DOHC
Cylinder arrangement Single cylinder, forward inclined
Displacement 250 cm
3 (8.80 Imp oz, 8.45 US oz)
Bore × stroke 77.0 × 53.6 mm (3.03 × 2.11 in)
Compression ratio 13.5 : 1
Starting system Kickstarter
Lubrication system: Dry sump
Oil type or grade: Engine oil Recommended brand: YAMALUBE
SAE10W-30, SAE10W-40, SAE10W-50
SAE15W-40, SAE20W-40 or SAE20W-50
API service SG type or higher,
JASO standard MA
Oil capacity: Engine oilPeriodic oil change 0.95 L (0.84 Imp qt, 1.00 US qt)
With oil filter replacement 1.05 L (0.92 Imp qt, 1.11 US qt)
Total amount 1.20 L (1.06 Imp qt, 1.27 US qt)
Coolant capacity (including all routes): 1.00 L (0.88 Imp qt, 1.06 US qt)
Air filter: Wet type element
Fuel: Type Premium unleaded gasoline only with a research octane
number of 95 or higher.
Tank capacity 6.4 L (1.4 Imp gal, 1.69 US gal)
2

2-13
TIGHTENING TORQUES
△Front brake disc M6 × 1.0 6 12 1.2 8.7
△ Rear brake disc M6 × 1.0 6 14 1.4 10
△ Footrest bracket and frame M10 × 1.25 4 55 5.5 40
△ Brake pedal M8 × 1.25 1 26 2.6 19
△ Rear brake master cylinder M6 × 1.0 2 10 1.0 7.2
Rear brake master cylinder cap M4 × 0.7 2 2 0.2 1.4
△ Rear brake hose union bolt M10 × 1.25 2 30 3.0 22
△ Rear wheel axle and axle nut M22 × 1.5 1 135 13.5 98
△ Nipple (spoke) —72 3 0.3 2.2
△ Rear wheel sprocket M8 × 1.25 6 42 4.2 30
△ Rear brake disc cover M6 × 1.0 2 10 1.0 7.2
△ Rear brake caliper protector M6 × 1.0 2 7 0.7 5.1
Drive chain puller adjust bolt and locknut M8 × 1.25 2 21 2.1 15
Engine mounting:
△ Engine and engine bracket (front) M10 × 1.25 1 53 5.3 38
△ Engine and frame (lower) M10 × 1.25 1 53 5.3 38
△ Upper engine bracket and frame M8 × 1.25 4 34 3.4 25
△ Front engine bracket and frame M8 × 1.25 4 34 3.4 25
△ Engine and engine bracket (upper) M10 × 1.25 2 55 5.5 40
Lower engine guard M6 × 1.0 3 10 1.0 7.2
CDI unit bracket M6 × 1.0 2 7 0.7 5.1
Cable guide and frame M6 × 1.0 2 7 0.7 5.1
△ Pivot shaft and nut M16 × 1.5 1 85 8.5 61
△ Relay arm and swingarm M14 × 1.5 1 70 7.0 50
△ Relay arm and connecting rod M14 × 1.5 1 80 8.0 58
△ Connecting rod and frame M14 × 1.5 1 80 8.0 58
△ Rear shock absorber and frame M10 × 1.25 1 56 5.6 40
△ Rear shock absorber and relay arm M10 × 1.25 1 53 5.3 38
△ Rear frame (upper) M8 × 1.25 2 32 3.2 23
△ Rear frame (lower) M8 × 1.25 2 32 3.2 23
△ Swingarm and brake hose holder M5 × 0.8 4 3 0.3 2.2
Upper drive chain tensioner M8 × 1.25 1 16 1.6 11
Lower drive chain tensioner M8 × 1.25 1 16 1.6 11
Drive chain support M6 × 1.0 3 7 0.7 5.1
△ Seal guard and swingarm M5 × 0.8 4 6 0.6 4.3
△ Fuel tank M6 × 1.0 1 9 0.9 6.5
△ Fuel cock M6 × 1.0 2 4 0.4 2.9
Seat set bracket and fuel tank M6 × 1.0 1 7 0.7 5.1
Fuel tank bracket and fuel tank M6 × 1.0 2 7 0.7 5.1
Side cover set bracket and fuel tank M6 × 1.0 2 7 0.7 5.1
Fitting band set screw and fuel tank M6 × 1.0 1 7 0.7 5.1
△ Air scoop and fuel tank M6 × 1.0 2 7 0.7 5.1
△ Air scoop and radiator guard M6 × 1.0 4 7 0.7 5.1
Air scoop and frame M6 × 1.0 2 7 0.7 5.1
Part to be tightened
Thread size Q'tyTightening torque
Nm m•kg ft•lb

3-3
MAINTENANCE INTERVALS
COOLING SYSTEMCheck coolant level and leakage ●●
Check radiator cap operation ●
Replace coolant ●Every two years
Inspect hoses ●
OUTSIDE NUTS AND BOLTS Retighten ●● Refer to "STARTING AND BREAK-
IN" section in the CHAPTER 1.
AIR FILTER Clean and lubricate ●● Use foam air-filter oil or equivalent oil.
Replace ●
OIL FILTER Replace ●●
OIL STRAINER Clean ●
ENGINE GUARD Replace ●Breakage
FRAME Clean and inspect ●●
FUEL TANK, COCK Clean and inspect ●●
BRAKES Adjust lever position and pedal
height ●●
Lubricate pivot point ●●
Check brake disc surface ●●
Check fluid level and leakage ●●
Retighten brake disc bolts, cali-
per bolts, master cylinder bolts
and union bolts ●●
Replace pads ●
Replace brake fluid ●Every one year
FRONT FORKS Inspect and adjust ●●
Replace oil ●● Suspension oil "S1"
Replace oil seal ●
FRONT FORK OIL SEAL AND
DUST SEAL Clean and lube ●● Lithium base grease
PROTECTOR GUIDE Replace ●
Item
After
break- in Every
race
(about 2.5
hours)
Every third
(about 7.5
hours) Every
fifth
(about 12.5
hours)
As re-
quired Remarks

3-5
PRE-OPERATION INSPECTION AND MAINTENANCE
PRE-OPERATION INSPECTION AND MAINTENANCE
Before riding for break-in operation, practice or a race, make sure the machine is in good operating condition.
Before using this machine, check the following points.
GENERAL INSPECTION AND MAINTENANCE
Item RoutinePage
Coolant Check that coolant is filled up to the radiator cap. Check the cool-
ing system for leakage. P.3-6 – 7
Fuel Check that a fresh gasoline is filled in the fuel tank. Check the fuel
line for leakage. P.1-13
Engine oil Check that the oil level is correct. Check the crankcase and oil line
for leakage.
P.3-9 – 10
Gear shifter and clutch Check that gears can be shifted correctly in order and that the
clutch operates smoothly. P.3-7
Throttle grip/Housing Check that the throttle grip operation and free play are correctly
adjusted. Lubricate the throttle grip and housing, if necessary. P.3-7 – 8
Brakes Check the play of front brake and ef fect of front and rear brake. P.3-14 – 16
Drive chain Check drive chain slack and alignment. Check that the drive chain
is lubricated properly.
P.3-17 – 18
Wheels Check for excessive wear and ti
re pressure. Check for loose
spokes and have no excessive play. P.3-20 – 21
Steering Check that the handlebar can be turned smoothly and have no ex-
cessive play. P.3-21 – 22
Front forks and rear shock
absorber Check that they operate smooth
ly and there is no oil leakage.
P.3-18 – 20
Cables (wires) Check that the clutch and throttle cables move smoothly. Check
that they are not caught when the handlebars are turned or when
the front forks travel up and down.
—
Exhaust pipe Check that the exhaust pipe is tightly mounted and has no cracks. P.4-3 – 4
Rear wheel sprocket Check that the rear whee l sprocket tightening bolt is not loose.P.3-17
Lubrication Check for smooth operation. Lubricate if necessary. P.3-23
Bolts and nuts Check the chassis and engine for loose bolts and nuts. P.1-15
Lead connectors Check that the CDI magneto, CDI
unit, and ignition coil are con-
nected tightly. P.1-7
Settings Is the machine set suitably for the
condition of the racing course
and weather or by taking into account the results of test runs be-
fore racing? Are inspection and maintenance completely done? P.7-1 – 10

3-10
ENGINE
Replacement steps:
a. Remove the oil filter element cov-er "1" and oil filter element "2".
b. Check the O-rings "3", if cracked or damaged, replace them with a
new one.
c. Install the oil filter element and oil filter element cover.
8. Install:
• O-ring "1"
• Oil strainer "2"
• Oil hose
• Bolt (oil hose)
• Oil hose clamp
9. Install: • Copper washer
• Oil filter element drain bolt
• Crankcase oil drain bolt • Oil tank drain bolt
• Lower engine guard
10. Fill: • Engine oil
11. Check: • Oil leakage
12. Install: • Oil filler cap
• Washer (oil tank)
• Bolt (oil tank)
13. Check: • Engine oil level
CHECKING THE OIL PRESSURE
1. Check: • Oil pressure
Checking steps:
a. Slightly loosen the oil pressure check bolt "1".
b. Start the engine and keep it idling
until oil starts to seep from the oil
pressure check bolt. If no oil
comes out after one minute, turn
the engine off so it will not seize.
c. Check oil passages and oil pump for damage or leakage.
d. Start the engine after solving the problem(s) and recheck the oil
pressure. e. Tighten the oil pressure check
bolt.
ADJUSTING THE PILOT SCREW
1. Adjust:• Pilot screw "1"
Adjustment steps:
To optimize the fuel flow at a smaller
throttle opening, each machine's pilot
screw has been individually set at the
factory. Before adjusting the pilot
screw, turn it in fully and count the
number of turns. Record this number
as the factory-set number of turns
out.
a. Turn in the pilot screw until it is lightly seated.
b. Turn out the pilot screw by the
factory-set number of turns.
ADJUSTING THE ENGINE IDLING
SPEED
1. Start the engine and thoroughly warm it up.
2. Adjust: • Engine idling speed
Adjustment steps:
a. Adjust the pilot screw. Refer to "ADJUSTING THE PI-
LOT SCREW" section.
Oil filter element cover:
10 Nm (1.0 m•kg, 7.2
ft•lb)
Oil strainer: 9 Nm (0.9 m•kg, 6.5
ft•lb)
Bolt (oil hose): 8 Nm (0.8 m•kg, 5.8
ft•lb)
Oil hose clamp: 2 Nm (0.2 m•kg, 1.4
ft•lb)
Oil filter element drain
bolt: 10 Nm (1.0 m•kg, 7.2
ft•lb)
Crankcase oil drain bolt: 20 Nm (2.0 m•kg, 14
ft•lb)
Oil tank drain bolt:18 Nm (1.8 m•kg, 13
ft•lb)
Lower engine guard: 10 Nm (1.0 m•kg, 7.2
ft•lb)
Oil quantity: Periodic oil change:0.95 L (0.84 Imp qt,
1.00 US qt)
With oil filter replace-
ment:
1.05 L (0.92 Imp qt,
1.11 US qt)
Total amount:
1.20 L (1.06 Imp qt,
1.27 US qt)
Bolt (oil tank): 4 Nm (0.4 m•kg, 2.9
ft•lb)
Oil pressure check bolt: 10 Nm (1.0 m•kg, 7.2
ft•lb)
Pilot screw (example): 1-3/4 turns out