2002 YAMAHA XVS125 maintenance

6-7
PERIODIC MAINTENANCE AND MINOR REPAIR
6 2. Pull the rear of the panel out with
the key inserted in the lock, and
then slide the panel forward to
release it in the front.To install the panel
1. Secure the front of the panel,
and then push the rear of the
panel in with the key inserted in
the lock.
2. Turn the key counterclockwise to
the original position, remove it,
and then close the lock cover.
EAU03329
Checking the spark plugs
Spark plugs, checking
The spark plugs are important engine
components, which are easy to
check. Since heat and deposits will
cause any spark plug to slowly erode,
the spark plugs should be removed
and checked in accordance with the
periodic maintenance and lubrication
chart. In addition, the condition of the
spark plugs can reveal the condition
of the engine.
To remove a spark plug
1. Remove the spark plug cap.
1
1. Spark plug cap
5JX-28199-E2 honbun 10/11/01 2:14 PM Page 37

6-8
PERIODIC MAINTENANCE AND MINOR REPAIR
62. Remove the spark plug as
shown, with the spark plug
wrench included in the owner’s
tool kit.To check the spark plugs
1. Check that the porcelain insulator
around the center electrode on
each spark plug is a medium-to-
light tan (the ideal color when the
motorcycle is ridden normally).2. Check that all spark plugs
installed in the engine have the
same color.NOTE:
If any 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.3. Check each spark plug for elec-
trode erosion and excessive car-
bon or other deposits, and
replace it if necessary.To install a spark plug
1. Measure the spark plug gap with
a wire thickness gauge and, if
necessary, adjust the gap to
specification.
2. Clean the surface of the spark
plug gasket and its mating sur-
face, 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.
1
a
1. Spark plug wrencha. Spark plug gap
Specified spark plug:
CR7HSA (NGK)
U22FSR-U (DENSO)
Spark plug gap:
0.6–0.7 mm
5JX-28199-E2 honbun 10/11/01 2:14 PM Page 38

6-9
PERIODIC MAINTENANCE AND MINOR REPAIR
6
NOTE:
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.
EAU04433
Engine oil and oil filter
element
Engine oil and oil filter element
The 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 periodic maintenance
and lubrication chart.
To check the engine oil level
1. Place the motorcycle on a level
surface and hold it in an upright
position.NOTE:
Make sure that the motorcycle 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 for
several 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.
NOTE:
The engine oil should be between the
minimum and maximum level marks.4. If the engine oil is below the min-
imum level mark, add sufficient
oil of the recommended type to
raise it to the correct level.
2
1
3
1. Oil level check window
2. Maximum level mark
3. Minimum level mark
Tightening torque:
Spark plug:
12.5 Nm (1.25 m0kgf)
5JX-28199-E2 honbun 10/11/01 2:14 PM Page 39

6-10
PERIODIC MAINTENANCE AND MINOR REPAIR
6To change the engine oil (with or
without oil filter element replace-
ment)
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.3. Remove the engine oil filler cap
and drain bolt to drain the oil
from the crankcase.
NOTE:
Skip steps 4-6 if the oil filter element
is not being replaced.
4. Remove the oil filter element
cover by removing the bolts.
1
1
1
1. Engine oil filler cap 1. Engine oil drain bolt 1. Bolt (×3)
5JX-28199-E2 honbun 10/11/01 2:14 PM Page 40

6-11
PERIODIC MAINTENANCE AND MINOR REPAIR
6 5. Remove and replace the oil filter
element and O-ring.
6. Install the oil filter element cover
by installing the bolts, then tight-
ening them to the specified
torque.
NOTE:
Make sure that the O-ring is properly
seated.
7. Install the engine oil drain bolt,
and then tighten it to the speci-
fied torque.
8. Add the specified amount of the
recommended engine oil, and
then install and tighten the oil
filler cap.
ECA00105
cC8In order to prevent clutch slip-
page (since the engine oil also
lubricates the clutch), do not
mix any chemical additives
with the oil or use oils of grade
“CD” or higher. In addition, do
not use oils labeled “ENERGY
CONSERVING II” or higher.
8Make sure that no foreign
material enters the crankcase.
2
1
1. Oil filter element
2. O-ring
Tightening torque:
Oil filter element cover bolt:
10 Nm (1.0 m0kgf)
Tightening torque:
Engine oil drain bolt:
34 Nm (3.4 m0kgf)
Recommended engine oil:
See page 8-1.
Oil quantity:
With oil filter element
replacement:
1.6 L
Without oil filter element
replacement:
1.4 L
Total amount (dry engine):
1.75 L
5JX-28199-E2 honbun 10/11/01 2:14 PM Page 41

6-12
PERIODIC MAINTENANCE AND MINOR REPAIR
69. 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.
10. Turn the engine off, and then
check the oil level and correct it if
necessary.
EAU03330
Cleaning the air filter
elementThe air filter element should be
cleaned at the intervals specified in
the periodic maintenance and lubrica-
tion chart. Clean the air filter element
more frequently if you are riding in
unusually wet or dusty areas.
1. Remove the air filter case by
removing the bolts and loosening
the clamp screw.2. Remove the air filter case cover
by removing the screws.
1
2
1
1
1. Bolt (×2)
2. Clamp screw1. Screw (×5)
5JX-28199-E2 honbun 10/11/01 2:14 PM Page 42

6-13
PERIODIC MAINTENANCE AND MINOR REPAIR
6 3. Remove the air filter element by
removing the screws.4. Lightly tap the air filter element to
remove most of the dust and dirt,
and then blow the remaining dirt
out with compressed air as
shown. If the air filter element is
damaged, replace it.
5. Install the air filter element by
inserting it into the air filter case,
then installing the screws.
EC000082
cC8Make sure that the air filter ele-
ment is properly seated in the
air filter case.
8The engine should never be
operated without the air filter
element installed, otherwise
the pistons and/or cylinders
may become excessively
worn.6. Install the air filter case cover by
installing the screws.
7. Install the air filter case by
installing the bolts.
8. Tighten the clamp screw.
1
2
1. Air filter element
2. Screw (×2)
5JX-28199-E2 honbun 10/11/01 2:14 PM Page 43

6-14
PERIODIC MAINTENANCE AND MINOR REPAIR
6
EAU00629
Adjusting the carburetor
Carburetor, adjusting
The carburetor is an important part of
the engine and requires very sophisti-
cated adjustment. Therefore, most
carburetor adjustments should be left
to a Yamaha dealer, who has the
necessary professional knowledge
and experience. The adjustment
described in the following section,
however, may be serviced by the
owner as part of routine mainte-
nance.
EC000094
cCThe carburetor has been set and
extensively tested at the Yamaha
factory. Changing these settings
without sufficient technical knowl-
edge may result in poor perfor-
mance of or damage to the engine.
EAU01168
Adjusting the engine idling
speed
Engine idling speed
The engine idling speed must be
checked and, if necessary, adjusted
as follows at the intervals specified in
the periodic maintenance and lubrica-
tion chart.NOTE:
A diagnostic tachometer is needed to
make this adjustment.1. Attach the tachometer to the
spark plug lead.
2. Start the engine and warm it up
for several minutes at 1,000–
2,000 r/min while occasionally
revving it to 4,000–5,000 r/min.NOTE:
The engine is warm when it quickly
responds to the throttle.
3. Check the engine idling speed
and, if necessary, adjust it to
specification by turning the throt-
tle stop screw. To increase the
engine idling speed, turn the
screw in direction a. To
decrease the engine idling speed,
turn the screw in direction b.NOTE:
If the specified idling speed cannot
be obtained as described above,
have a Yamaha dealer make the
adjustment.
1b
a
1. Throttle stop screw
Engine idling speed:
1,250–1,450 r/min
5JX-28199-E2 honbun 10/11/01 2:14 PM Page 44