engine YAMAHA YBR250 2007 Owner's Manual

6-7
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PERIODIC MAINTENANCE AND MINOR REPAIR
1. Remove the seat. (See page 3-9.)
2. Remove the screws, and then pullthe panel to the outside as shown.To install the panel1. Place the panel in the original position, and install the screws.
2. Install the seat.
EAU19630
Checking the spark plugl
The spark plug is an important
engine component, which is easy
to check. Since heat and deposits
will cause any spark plug to slowly
erode, the spark plug should be
removed and checked in
accordance with the periodic
maintenance and lubrication chart.
In addition, the condition of the
spark plug can reveal the condition
of the engine.
To remove the spark plug 1. Remove cowling. (See page 6-6.)
1. Spark plug cap2. Remove the spark plug cap.
3. Remove the spark plug as shown, with the spark plug wrench included
in the owner’s tool kit.
1. Spark plug wrenchTo check the spark plug1. Check that the porcelain insulator around the center electrode of the
spark plug is a medium-to-light tan
(the ideal color when the
motorcycle is ridden normally).If the spark plug shows a distinctly
different color, the engine could be
defective. Do not attempt to diagnose
such problems yourself. Instead, have
a Yamaha dealer check the motorcycle.2. Check the spark plug for electrodeerosion and excessive carbon or
other deposits, and replace it if
necessary.
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6-8
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PERIODIC MAINTENANCE AND MINOR REPAIRSpecified spark plug:NGK / DR8EATo install the spark plug
1. Measure the spark plug gap with a wire thickness gauge and, if
necessary, adjust the gap to
specification.1. Spark plug gapSpark plug gap:0.6~0.7mm (0.024-0.028 in)2. Clean the surface of the spark plug
gasket and its mating surface, and
then wipe off any grime from the
spark plug threads.
3. Install the spark plug with the spark plug wrench, and then
tighten it to the specified torque. Tightening torque:
Spark plug:17.5 Nm (1.75 m.kgf, 13 ft.lbt)
If a torque wrench is not available when
installing a spark plug, a good estimate
of the correct torque is 1/4-1/2 turn past
finger tight. However, the spark plug
should be tightened to the specified
torque as soon as possible.4. Install the spark plug cap.
5. Install the cowling.
EAU37801
Engine oil and oil filter
elementThe engine oil level should be checked
before each ride. In addition, the oil must
be changed and the oil filter element
replaced at the intervals specified in the
General periodic maintenance and
lubrication chart.
To check the engine oil level 1. Place the vehicle on a level surface and hold it in an upright
position.Make sure that the vehicle is positioned
straight up when checking the oil level.
A slight tilt to the side can result in a
false reading.2. Start the engine, warm it up forseveral minutes, and then turn it
off.
3. Wait a few minutes until the oil settles, and then check the oil level
through the check window located
at the bottom-right side of the
crankcase.
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6-9
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PERIODIC MAINTENANCE AND MINOR REPAIR
The engine oil should be between the
minimum and maximum level marks.
12
3
1. Engine oil filler cap
2. Maximum level mark
3. Minimum level mark4. If the engine oil is below the minimum level mark, add sufficient
oil of the recommended type to
raise it to the correct level.
To change the engine oil (with or
without oil filter element
replacement) 1. Start the engine, warm it up for several minutes, and then turn it
off.
2. Place an oil pan under the engine to collect the used oil.
1
1. Dipstick3. Remove the engine oil filler bolt anddrain bolt to drain the oil from the
crankcase.
-2-3-4-5
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1. Engine oil drain boltCheck the washer for damage and
replace it if necessary.
4. Remove the oil filter element drainbolt to drain the oil from the oil filter
element.Skip steps 5-7 if the oil filter element is
not being replaced.5. Remove the oil filter element coverby removing the bolts.1. Oil filter element cover bolts
2. Oil filter element drain bolt6. Remove and replace the oil filterelement and O-rings.
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6-10
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PERIODIC MAINTENANCE AND MINOR REPAIR
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1. Oil filter element
2. O-ringMake sure that the O-rings are properly
seated.7. Install the oil filter element coverby installing the bolts, then
tightening them to the specified
torque.Tightening torque:Oil filter element cover bolt: 10 Nm (1,0 m.kgf, 7.4 ft.lbf)8. Install the engine oil drain bolt, and
then tighten it to the specified
torque.
9. Install the oil filter element drain bolt, and then tighten it to the
specified torque.
Tightening torque:Engine oil drain bolt: 20 Nm (2.0 m.kgf, 15 ft.lbf)
Oil filter element drain bolt: 7 Nm (0.7 m.kgf, 5.25 ft.lbf)10. Add the specified amount of the
recommended engine oil, and then
install and tighten the oil filler bolt.Recommended engine oil:See page 8-1
Oil quantity: Without oil filter element
replacement:1.35 L (1.43 US qt) (1.19
Imp.qt)
With oil filter element replacement:1.45 L (1.53 US qt) (1.28
Imp.qt)
ECA11620
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In order to prevent clutch
slippage (since the engine oil
also lubricates the clutch), do not
mix any chemical additives. Do
not use oils with a diesel
specification of “CD” or oils of a
higher quality than specified. In addition, do not use oils labeled
“ENERGY CONSERVING II” or
higher.
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Make sure that no foreign
material enters the crankcase.
11. Start the engine, and then let it idle
for several minutes while checking
it for oil leakage. If oil is leaking,
immediately turn the engine off and
check for the cause.
12. Turn the engine off, and then check the oil level and correct it if
necessary.
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6-11
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PERIODIC MAINTENANCE AND MINOR REPAIR
EAU20880
Cleaning the air filter elementThe air filter should be cleaned at the
specified intervals. It should be cleaned
more frequently when riding in unusually
wet or dusty areas.1. Remove panel B. (See page 6-6.)
1 2
2
1. Air filter case cover
2. Screw2. Remove the air filter case by
removing the screws.
3. Remove the air filter from the case.
1
1. Air filter element
4. Remove the air filter element from its guide and clean it with solvent.
After cleaning, remove the
remaining solvent by squeezing
the element.5. Apply recommended oil to theentire surface of the element and
squeeze out the excess oil. It
should be wet but not dripping.Recommended oil:Engine oil6. Insert the air filter element guide
into the air filter and install it in the
case.
7. Install the air filter case cover and panel by installing the screws.
ECA10480
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Make sure that the air filter
element is properly seated in the
air filter case.
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The engine should never be
operated without the air filter
element installed, otherwise the
piston(s) and/or cylinder(s) may
become excessively worn.
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6-12
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PERIODIC MAINTENANCE AND MINOR REPAIR
EAU21311
Checking the engine idling
speedThe engine idling speed must be
checked as follow and, if necessary,
adjusted by a Yamaha dealer at the
intervals specified in the periodic
maintenance and lubrication chart.
Start the engine and warm it up for
several minutes at 1000-2000 r/min while
occasionally revving it to 4000-5000 r/
min.The engine is warm when it quickly
responds to the throttle.Engine idling speed:1.300 - 1.500 r/min.
EAU21382
Checking the throttle cable
free play
1
1. Throttle cable free playThe throttle cable free play should
measure 3.0 - 5.0 mm (0.12 - 0.20 in)
at the throttle grip. Periodically check the
throttle cable free play and, if necessary,
have a Yamaha dealer adjust it.
EAU21401
Valve clearancel
The valve clearance changes with
use, resulting in improper air-fuel
mixture and/or engine noise. To
prevent this from occurring, the
valve clearance must be adjusted
by a Yamaha dealer at the intervals
specified in the periodic
maintenance and lubrication chart.
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6-19
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PERIODIC MAINTENANCE AND MINOR REPAIR
EAU22760
Drive chain slackThe drive chain slack should be checked
before each ride and adjusted if
necessary.
EAU22772
To check the drive chain slack
1
1. Drive chain slack1. Place the motorcycle on thesidestand.When checking and adjusting the drive
chain slack, there should be no weight
on the motorcycle.2. Shift the transmission into theneutral position.
3. Move the rear wheel by pushing the motorcycle to locate the tightest portion of the drive chain,
and then measure the drive chain
slack as shown.
Drive chain slack:
25.0 - 35.0 mm (0.98 - 1.38 in)4. If the drive chain slack is incorrect,
adjust it as follows.
EAU22821
To adjust the drive chain slack1. Axle nut
2. Drive chain slack adjusting nut
3. Locknut
4. Alignment marks1. Loosen the brake pedal free playadjusting nut, axle nut, and locknut
at each end of the swingarm.
2. To tighten the drive chain, turn the adjusting nut at each end of the swingarm in direction (a). To loosen
the drive chain, turn the adjusting
nut at each end of the swingarm in
direction (b), and then push the rear
wheel forward.
Using the alignment marks on each side
of the swingarm, make sure that both
adjusting nuts are in the same position
for proper wheel alignment.
ECA10570
Improper drive chain slack will
overload the engine as well as other
vital parts of the motorcycle and can
lead to chain slippage or breakage.
To prevent this from occurring, keep
the drive chain slack within the
specified limits.3. Tighten both locknuts and the axle
nut to the specified torques.
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6-20
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PERIODIC MAINTENANCE AND MINOR REPAIRTightening torques:Locknut:
16 Nm (1.6 m.kgf, 12 ft.lbt)
Axle nut: 104 Nm (10.4 m.kgf, 77 ft.lbt)4. Adjust the brake pedal free play.
(See page 6-16.)
EWA10660
After adjusting the brake pedal free
play, check the operation of the brake
light.
EAU23022
Cleaning and lubricating the
drive chainThe drive chain must be cleaned and
lubricated at the intervals specified in
the periodic maintenance and lubrication
chart, otherwise it will quickly wear out,
especially when riding in dusty or wet
areas. Service the drive chain as follows.
ECA10581
The drive chain must be lubricated
after washing the motorcycle and
riding in the rain.1. Clean the drive chain with keroseneand a small soft brush.
ECA11120
To prevent damaging the O-rings, do
not clean the drive chain with steam
cleaners, high-pressure washers or
inappropriate solvents.2. Wipe the drive chain dry.
3. Thoroughly lubricate the drive chain with a special O-ring chain
lubricant.
ECA11110
Do not use engine oil or any other
lubricants for the drive chain, as they
may contain substances that could
damage the O-rings.
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6-21
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PERIODIC MAINTENANCE AND MINOR REPAIR
EAU23100
Checking and lubricating the
cablesThe operation of all control cables and
the condition of the cables should be
checked before each ride, and the
cables and cable ends should be
lubricated if necessary. If a cable is
damaged or does not move smoothly,
have a Yamaha dealer check or replace
it.Recommended lubricant:Engine oil
EWA10720
Damage to the outer sheath may
interfere with proper cable operation
and will cause the inner cable to rust.
Replace a damaged cable as soon as
possible to prevent unsafe
conditions.
EAU23111
Checking and lubricating the
throttle grip and cableThe operation of the throttle grip should
be checked before each ride. In addition,
the cable should be lubricated at the
intervals specified in the periodic
maintenance chart.
EAU23140
Checking and lubricating the
brake and clutch levers
1
2
1. Brake lever
2. Lubrication point1. Clutch lever
2. Lubrication pointThe operation of the brake and clutch
levers should be checked before each
ride, and the lever pivots should be
lubricated if necessary.
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6-24
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PERIODIC MAINTENANCE AND MINOR REPAIR
EAU23280
Checking the steeringWorn or loose steering bearings may
cause danger. Therefore, the operation
of the steering must be checked as
follows at the intervals specified in the
periodic maintenance and lubrication
chart.1. Place a stand under the engine to raise the front wheel off the ground.
EWA10750
Securely support the motorcycle so
that there is no danger of it falling
over.2. Hold the lower ends of the front forklegs and try to move them forward
and backward. If any free play can
be felt, have a Yamaha dealer
check or repair the steering.
EAU23290
Checking the wheel bearingsThe front and rear wheel bearings must
be checked at the intervals specified in
the periodic maintenance and lubrication
chart. If there is play in the wheel hub or
if the wheel does not turn smoothly,
have a Yamaha dealer check the wheel
bearings.
EAUW0100
BatteryThe battery is located under the seat.
(See page 3-9).
This model is equipped with a sealed
type (MF) battery, which does not require
any maintenance. There is no need to
check the electrolyte or to add distilled
water.
ECA10620
Never attempt to remove the battery
cell seals, as this would permanently
damage the battery.
EWA10760
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Electrolyte is poisonous and
dangerous since it contains
sulfuric acid, which causes
severe burns. Avoid any contact
with skin, eyes or clothing and
always shield your eyes when
working near batteries. In case
of contact, administer the
following FIRST AID.l
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EXTERNAL: Flush with plenty
of water.
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INTERNAL: Drink large
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