2004 YAMAHA XVS125 check engine

PERIODIC MAINTENANCE AND MINOR REPAIR
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2. Pull the rear of the panel out with
the key inserted in the lock, and
then slide the panel forward to re-
lease it in the front.
To install the panel
1. Secure the front of the panel, andthen 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 panel lock cover.

EAU19543
Checking the spark plugs
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 mainte-
nance and lubrication chart. In addition,
the condition of the spark plugs can re-
veal the condition of the engine.
To remove a spark plug
1. Remove the spark plug cap.
2. Remove the spark plug as shown,
with the spark plug wrench includ-
ed in the owner’s tool kit.
1. Lock cover
2. Unlock.
1
2

1. Spark plug cap
1

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9 To check the spark plugs
1. Check that the porcelain insulator
around the center electrode on
each spark plug is a medi-
um-to-light tan (the ideal color
when the vehicle is ridden normal-
ly).
2. Check that all spark plugs installed
in the engine have the same color.
NOTE:

If any spark plug shows a distinctly dif-
ferent color, the engine could be defec-
tive. Do not attempt to diagnose such
problems yourself. Instead, have a
Yamaha dealer check the vehicle.
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 nec-
essary, adjust the gap to specifica-
tion.
2. Clean the surface of the spark pluggasket 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 tight-
en it to the specified torque.
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 speci-
fied torque as soon as possible.
4. Install the spark plug cap.
1. Spark plug wrench
1

Specified spark plug:
NGK/CR7HSA
DENSO/U22FSR-U
1. Spark plug gap
Spark plug gap:
0.6–0.7 mm (0.024–0.028 in)
1

Tightening torque:
Spark plug:
12.5 Nm (1.25 m·kgf, 9 ft·lbf)

PERIODIC MAINTENANCE AND MINOR REPAIR
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EAU19751
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 ele-
ment replaced at the intervals specified
in the periodic maintenance and lubri-
cation chart.
To check the engine oil level
1. Place the vehicle on a level sur-
face and hold it in an upright posi-
tion.
NOTE:

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 for
several minutes, and then turn it
off.
3. Wait a few minutes until the oil set-
tles, 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 mini-
mum 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 replace-
ment)
1. Start the engine, warm it up for
several minutes, and then turn it
off.
2. Place an oil pan under the engineto 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
1. Engine oil level check window
2. Maximum level mark
3. Minimum level mark
2
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3

1. Engine oil filler cap
1. Engine oil drain bolt
11

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for several minutes while checking
it for oil leakage. If oil is leaking, im-
mediately 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.

EAU32401
Cleaning the air filter element
The air filter element should be cleaned
at the intervals specified in the periodic
maintenance and lubrication chart.
Clean the air filter element more fre-
quently if you are riding in unusually
wet or dusty areas.
1. Remove the air filter case by re-
moving the bolts and loosening the
clamp screw.
2. Remove the air filter case cover by
removing the screws.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
1. Bolt
2. Clamp screw
1
2

1. Screw
1. Air filter element
2. Screw
1
1
1
2(×2)

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EAU21340
Adjusting the 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 lubrication
chart.
The engine should be warm before
making this adjustment.
NOTE:


The engine is warm when it quickly
responds to the throttle.

A diagnostic tachometer is needed
to make this adjustment.
1. Attach the tachometer to the spark
plug lead.
2. Check the engine idling speed
and, if necessary, adjust it to spec-
ification by turning the throttle stop
screw. To increase the engine
idling speed, turn the screw in di-
rection (a). To decrease the en-
gine 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.
EAU21380
Adjusting the throttle cable
free play
The throttle cable free play should mea-
sure 3.0–5.0 mm (0.12–0.20 in) at the
throttle grip. Periodically check the
throttle cable free play and, if neces-
sary, have a Yamaha dealer adjust it.
1. Throttle stop screw
Engine idling speed:
1250–1450 r/min
1
(a) (b)

1. Throttle cable free play
1

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EAU21400
Adjusting the valve clearance
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.
EAU21540
Tires
To maximize the performance, durabil-
ity, and safe operation of your motorcy-
cle, note the following points regarding
the specified tires.
Tire air pressure
The tire air pressure should be checked
and, if necessary, adjusted before each
ride.
WARNING

EWA10500

The tire air pressure must be
checked and adjusted on cold
tires (i.e., when the temperature
of the tires equals the ambient
temperature).

The tire air pressure must be ad-
justed in accordance with the
riding speed and with the total
weight of rider, passenger, car-
go, and accessories approved
for this model.
WARNING

EWA11020
Because loading has an enormous
impact on the handling, braking,
performance and safety characteris-
tics of your motorcycle, you should
keep the following precautions in
mind.

NEVER OVERLOAD THE MO-
TORCYCLE! Operation of an Tire air pressure (measured on
cold tires):
0.0–90.0 kg (0–198 lb) :
Front:
175 kPa (25 psi) (1.75 kgf/cm
2
)
Rear:
200 kPa (29 psi) (2.00 kgf/cm
2
)
90.0–183.0 kg (198–404 lb) :
Front:
175 kPa (25 psi) (1.75 kgf/cm
2
)
Rear:
200 kPa (29 psi) (2.00 kgf/cm
2
)
Maximum load*:
183.0 kg (404 lb)
* Total weight of rider, passenger,
cargo and accessories

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2. To tighten the drive chain, turn the
adjusting nut at each end of the
swingarm in direction (a). To loos-
en the drive chain, turn the adjust-
ing nut at each end of theswingarm in direction (b), and then
push the rear wheel forward.
NOTE:

Using the alignment marks on each
side of the swingarm, make sure that
both adjusting nuts are in the same po-
sition for proper wheel alignment.
CAUTION:

ECA10570
Improper drive chain slack will over-
load the engine as well as other vital
parts of the motorcycle and can lead
to chain slippage or breakage. To
prevent this from occurring, keepthe drive chain slack within the
specified limits.
3. Tighten both locknuts and the axle
nut to the specified torques.
4. Adjust the brake pedal free play.
(See page 6-17.)
WARNING

EWA10660
After adjusting the brake pedal free
play, check the operation of the
brake light.
1. Brake pedal free play adjusting nut
2. Locknut
1. Axle nut
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1

1. Drive chain slack adjusting nut
2. Alignment marks
3. Locknut
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(a) (b)

Tightening torques:
Locknut:
16 Nm (1.6 m·kgf, 11.6 ft·lbf)
Axle nut:
104 Nm (10.4 m·kgf, 75 ft·lbf)

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EAU23020
Lubricating the drive chain
The drive chain must be cleaned and
lubricated at the intervals specified in
the periodic maintenance and lubrica-
tion chart, otherwise it will quickly wear
out, especially when riding in dusty or
wet areas. Service the drive chain as
follows.
CAUTION:

ECA10580
The drive chain must be lubricated
after washing the motorcycle or
riding in the rain.
1. Clean the drive chain with kero-
sene and a small soft brush.
CAUTION:

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.
CAUTION:

ECA11110
Do not use engine oil or any other lu-
bricants for the drive chain, as they
may contain substances that could
damage the O-rings.
EAU23100
Checking and lubricating the
cables
The operation of all control cables and
the condition of the cables should be
checked before each ride, and the ca-
bles and cable ends should be lubricat-
ed if necessary. If a cable is damaged
or does not move smoothly, have a
Yamaha dealer check or replace it.
WARNING

EWA10720
Damage to the outer sheath may in-
terfere with proper cable operation
and will cause the inner cable to
rust. Replace a damaged cable as
soon as possible to prevent unsafe
conditions.
Recommended lubricant:
Engine oil