2005 YAMAHA YZ250LC recommended oil

1-4
IMPORTANT INFORMATION
GEN
INFO
EC133000
GASKETS, OIL SEALS AND O-RINGS
1. All gaskets, oil seals, and O-rings should be
replaced when an engine is overhauled. All
gasket surfaces, oil seal lips, and O-rings
must be cleaned.
2. Properly oil all mating parts and bearings
during reassembly. Apply grease to the oil
seal lips.
EC134000
LOCK WASHERS/PLATES AND COTTER
PINS
1. All lock washers/plates 1and cotter pins
must be replaced when they are removed.
Lock tab(s) should be bent along the bolt or
nut flat(s) after the bolt or nut has been
properly tightened.
EC135001
BEARINGS AND OIL SEALS
1. Install the bearing (s) 1and oil seal (s) 2
with their manufacturer’s marks or numbers
facing outward. (In other words, the
stamped letters must be on the side
exposed to view.) When installing oil seal(s),
apply a light coating of light-weight lithium
base grease to the seal lip(s). Oil the bear-
ings liberally when installing.
cC
Do not use compressed air to spin the
bearings dry. This causes damage to the
bearing surfaces.
EC132000
ALL REPLACEMENT PARTS
1. We recommend to use Yamaha genuine
parts for all replacements. Use oil and/or
grease recommended by Yamaha for
assembly and adjustment.
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1-12
FUEL AND ENGINE MIXING OIL
GEN
INFO
EC160051
FUEL AND ENGINE MIXING OIL
Mix oil with the gas at the ratio specified below.
Always use fresh, name-brand gasoline, and mix
the oil and gas the day of the race. Do not use
premix that is more than a few hours old.
NOTE:
If knocking or pinging occurs, use a different
brand of gasoline or higher octane grade.
cC
Never mix two types of oil in the same
batch; clotting of the oil could result. If you
wish to change oil types, be sure to drain
the fuel tank and the carburetor float bowl
of old premix prior to filling with the new
type.
Fuel tank capacity:
8.0 L (1.76 Imp gal, 2.11 US gal)
Mixing oil
Recommended oil:
Yamalube “2-R”
(Yamalube racing 2-cycle oil)
Mixing ratio: 30 : 1
If unavailable, use an equivalent
type of oil.
Recommended fuel:
Premium unleaded gasoline
only with a research octane
number of 95 or higher.
1P8-9-30-1 19/5/04 9:00 AM Page 28

INSP
ADJ
3-13
TRANSMISSION OIL REPLACEMENT
3. Check:
9Transmission oil level
EC35K002
TRANSMISSION OIL REPLACEMENT
1. Start the engine and warm it up for several
minutes and wait for five minute.
2. Place the machine on a level place and hold
it on upright position by placing the suitable
stand under the engine.
3. Place a suitable container under the engine.
Transmission oil level checking steps:
9Remove the oil check bolt 1.
9Inspect the oil level.
NOTE:
Be sure the machine is positioned straight
up when inspecting the oil level.
w
Never attempt to remove the oil check bolt
just after high speed operation. The heat-
ed oil could spout out, causing danger.
Wait until the oil cools down.
Oil flows outOil level is correct.
Oil does not flow outOil level is low.
Add transmission
oil until oil flows
out.
9Inspect the gasket (oil check bolt), replace if
damaged.
9Tighten the oil check bolt.
Recommended oil:
Yamalube 4 (10W-30) or SAE
10W-30 type SE motor oil
Oil check bolt:
10 Nm (1.0 m•kg, 7.2 ft•lb)
1P8-9-30-3A 11/5/04 10:44 AM Page 34

INSP
ADJ
3-14
PILOT AIR SCREW ADJUSTMENT
4. Remove:
9Oil drain bolt 1
9Oil filler cap 2
Drain the transmission oil.
5. Install:
9Aluminum washer
9Oil drain bolt 1
6. Fill:
9Transmission oil
Recommended oil:
Yamalube 4 (10W-30) or SAE
10W-30 type SE motor oil
Oil capacity
(periodic oil change):
0.75 L (0.66 Imp qt, 0.79 US qt)
20 Nm (2.0 m•kg, 14 ft•lb)
7. Check:
9Oil leakage
8. Check:
9Transmission oil level
9. Install:
9Oil filler cap 2
EC35L021
PILOT AIR SCREW ADJUSTMENT
1. Adjust:
9Pilot air screw 1
Adjusting steps:
9Turn in the pilot air screw until it is lightly
seated.
9Turn out the pilot air screw by the factory-set
number of turns.
NOTE:
To optimize the fuel flow at a smaller throttle
opening, each machine’s pilot air screw has
been individually set at the factory. Before
adjusting the pilot air screw, turn it in fully and
count the number of turns. Record this num-
ber as the factory-set number of turns out.
Pilot air screw:
1 turn out
*7/8 turns out
(for reference only)
*For EUROPE
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5-24
CHASFRONT BRAKE AND REAR BRAKE
2. Install:
9Brake hose holder 1
9Screw (brake hose holder) 2
cC
After installing the brake hose holders,
make sure the brake hose does not contact
the spring (rear shock absorber). If it does,
correct its twist.
EC5A5620
Brake fluid
1. Fill:
9Brake fluid
Until the fluid level reaches “LOWER” level
line a.
w
9Use only the designated quality brake fluid:
otherwise, the rubber seals may deterio-
rate, causing leakage and poor brake per-
formance.
9Refill with the same type of brake fluid;
mixing fluids may result in a harmful chemi-
cal reaction and lead to poor performance.
9Be careful that water does not enter the
master cylinder when refilling. Water will
significantly lower the boiling point of the
fluid and may result in vapor lock.
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Brake fluid may erode painted surfaces or
plastic parts. Always clean up spilled fluid
immediately.
AFront
BRear
Recommended brake fluid:
DOT #4
1 Nm (0.1 m•kg, 0.7 ft•lb)
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5-28
CHASFRONT FORK
EC556000
HANDLING NOTE
NOTE:
The front fork requires careful attention. So it is
recommended that the front fork be maintained
at the dealers.
cC
To prevent an accidental explosion of air,
the following instructions should be ob-
served:
9The front fork with a built-in piston rod
has a very sophisticated internal con-
struction and is particularly sensitive to
foreign material.
Use enough care not to allow any foreign
material to come in when the oil is re-
placed or when the front fork is disassem-
bled and reassembled.
9Before removing the base valves or front
forks, be sure to extract the air from the air
chamber completely.
EC553000
REMOVAL POINTS
EC553311
Damper assembly
1. Loosen:
9Damper assembly 1
NOTE:
Before removing the front fork from the
machine, loosen the damper assembly with
the cap bolt ring wrench 2.
Cap bolt ring wrench:
YM-01501/90890-01501
1P8-9-30-5B 20/5/04 2:11 PM Page 6

5-32
CHASFRONT FORK
EC554600
Outer tube
1. Inspect:
9Outer tube 1
Score marks/Wear/DamageReplace.
Adjuster
1. Inspect:
9Adjuster 1
9O-ring 2
Wear/DamageReplace.
EC555000
ASSEMBLY AND INSTALLATIONEC5551D0
Front fork assembly
1. Wash the all parts in a clean solvent.
2. Stretch the damper assembly fully.
3. Fill:
9Front fork oil 1
To damper assembly.
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9Be sure to use recommended fork oil. If
other oils are used, they may have an ex-
cessively adverse effect on the front fork
performance.
9Never allow foreign materials to enter the
front fork.
Recommended oil:
Suspension oil “S1”
Oil capacity:
195cm
3(6.86 Imp oz, 6.59 US oz)
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5-38
CHASFRONT FORK
26. Install:
9Push rod 1
9Copper washer 2
9Adjuster 3
To damper assembly 4.
NOTE:
9While compressing the inner tube 5, set the
cap bolt ring wrench 7between the inner tube
and locknut 6.
9Fully finger tighten the adjuster onto the
damper assembly.
27. Inspect:
9Gap abetween adjuster 1and locknut 2.
Out of specificationRetighten and read-
just the locknut.
NOTE:
If the adjuster is installed out of specification,
proper damping force cannot be obtained.
28. Tighten:
9Adjuster (locknut) 1
NOTE:
Hold the locknut 2and tighten the adjuster with
specified torque.
29. Install:
9Adjuster 1
To inner tube.
30. Fill:
9Front fork oil 1
From outer tube top.
29 Nm (2.9 m•kg, 21 ft•lb)
55 Nm (5.5 m•kg, 40 ft•lb)
Gap a abetween adjuster and locknut
0.5~1.0mm (0.02~0.04 in)
Recommended oil:
Suspension oil "S1"
Standard oil amount:
245 cm
3(8.62 Imp oz, 8.28 US oz)
Extent of adjustment:
200
~300 cm3(7.04~10.6 Imp oz,
6.76~10.1 US oz)
Cap bolt ring wrench:
YM-01501/90890-01501
1P8-9-30-5B 20/5/04 2:11 PM Page 26