2004 YAMAHA BT1100 light

EAU00462PERIODIC MAINTENANCE AND MINOR REPAIR
To install a spark plug
1. Measure the spark plug gap with a
wire thickness gauge and, if neces-
sary, adjust the gap to specification.
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.
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 fin-
ger tight. However, the spark plug should
be tightened to the specified torque as
soon as possible.
4. Install the spark plug cap.
5. Place the spark plug cover in the orig-
inal position.
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6
a. Spark plug gap
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 differ-
ent 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 electrode
erosion and excessive carbon or oth-
er deposits, and replace it if neces-
sary.
Specified spark plug:
BPR7ES (NGK) or
W22EPR-U (DENSO)
Tightening torque:
Spark plug:
20 Nm (2.0 m·kgf)
Spark plug gap:
0.7-0.8 mm

EAU00462
1. Engine oil filler cap
PERIODIC MAINTENANCE AND MINOR REPAIR
1
NOTE:
Make sure that the motorcycle is posi-
tioned 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 sever-
al 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-left side of the crankcase.
NOTE:
The engine oil should be between the min-
imum and maximum level marks.
4. 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 without oil
filter element replacement
1. Start the engine, warm it up for sever-
al 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.
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EAU01712
Engine oil and oil filter element
The engine oil level should be checked be-
fore 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 sur-
face and hold it in an upright position.
1. Engine oil level window
2. Maximum level mark
3. Minimum level mark

EAU00462PERIODIC MAINTENANCE AND MINOR REPAIR
EC000072
•In order to prevent clutch slippage
(since the engine oil also lubri-
cates the clutch), do not mix any
chemical additives with the oil or
use oils of a higher grade than
“CD”. In addition, do not use oils
labeled "ENERGY CONSERVING II"
or higher.
•Make sure that no foreign material
enters the crankcase.
CAUTION:6. Start the engine, and then let it idle for
several minutes while checking it for
oil leakage. If oil is leaking, immedi-
ately turn the engine off and check for
the cause.
NOTE:
After the engine is started, the engine oil
level warning light should go off if the oil
level is sufficient.
EC000067
If the oil level warning light flickers or
remains on, immediately turn the
engine off and have a Yamaha dealer
check the vehicle.
7. Turn the engine off, and then check
the oil level and correct it if neces-
sary.
NOTE:
Have a Yamaha dealer replace the oil filter
element when necessary.
CAUTION:
1. Engine oil drain bolt
6-8
6
1
4. Install the engine oil drain bolt, and
then tighten it to the specified torque.
5. Add the specified amount of the rec-
ommended engine oil, and then in-
stall and tighten the oil filler cap. Tightening torque:
Engine oil drain bolt:
43 Nm (4.3 m·kgf)
Recommended engine oil:
See page 8-1.
Oil quantity:
Without oil filter element
replacement:
3.0 L
With oil filter element
replacement:
3.1 L
Total amount (dry engine):
3.6 L

EAU00462PERIODIC MAINTENANCE AND MINOR REPAIR
3
1 2
To check the final gear oil level
1. Place the motorcycle on a level sur-
face and hold it in an upright position.
NOTE:
•The final gear oil level must be
checked on a cold engine.
•Make sure that the motorcycle is posi-
tioned straight up when checking the
oil level. A slight tilt to the side can
result in a false reading.2. Remove the oil filler bolt, and then
check the oil level in the final gear
case.
NOTE:
The oil level should be at the brim of the
filler hole.
3. If the oil is below the brim of the filler
hole, add sufficient oil of the recom-
mended type to raise it to the correct
level.
To change the final gear oil
1. Place an oil pan under the final gear
case to collect the used oil.
2. Remove the oil filler bolt and drain
bolt to drain the oil from the final gear
case.
6-9
6
1. Final gear oil drain bolt
2. Final gear oil filler bolt
3. Oil level
EAU04083
Final gear oil
The final gear case must be checked for oil
leakage before each ride. If any leakage is
found, have a Yamaha dealer check and
repair the motorcycle. In addition, the final
gear oil level must be checked and the oil
changed as follows at the intervals speci-
fied in the periodic maintenance and lubri-
cation chart.
EW000066WARNING0
•Make sure that no foreign material
enters the final gear case.
• Make sure that no oil gets on the
tire or wheel.

PERIODIC MAINTENANCE AND MINOR REPAIR
23
1
5. Remove the air filter case cover by
removing the screws.
6. Pull the air filter element out.
7. Lightly tap the air filter element to re-
move most of the dust and dirt, and
then blow the remaining dirt out with
compressed air as shown. If the air fil-
ter element is damaged, replace it.
8. Insert the air filter element into the air
filter case.
1. Screw
2. Air filter case cover
3. Air filter
ECA00089
The engine should never be operated
without the air filter element installed,
otherwise the piston(s) and/or cylin-
der(s) may become excessively worn.
9. Install the air filter case cover by in-
stalling the screws.
10. Install the fuel tank by installing the
bolts.
11. Install the panels.
CAUTION:
EAU00462
6-11
6
4. Lift the fuel tank to position it away
from the air filter case. (Do not dis-
connect the fuel hoses!).
EW000071WARNING0
Make sure that the fuel tank is well sup-
ported.
Do not tilt or pull the fuel tank too much,
otherwise the fuel hoses may come
loose, which could cause fuel leakage.

EAU00462PERIODIC MAINTENANCE AND MINOR REPAIR
128
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EAUB0012
Replacing the fuses
The fuse box is located under the seat.
(See page 3-13 for seat removal and in-
stallation procedures). If a fuse is blown,
replace it as follows.
1. Turn the key to “
B” (OFF) and turn
off the electrical circuit in question.
2. Remove the blown fuse, and then in-
stall a new fuse of the specified am-
perage.
1. Screw (x 2)
2. Storage compartment
EC000103
Do not use a fuse of a higher amperage
rating than recommended to avoid
causing extensive damage to the elec-
trical system and possibly a fire.
3. Turn the key to “
I” (ON) and turn on
the electrical circuit in question to
check if the device operates.
4. If the fuse immediately blows again,
have a Yamaha dealer check the
electrical system.
CAUTION:
1. Fuse box cover
2. Main fuse
3. Headlight fuse
4. Signaling system fuse
5. Ignition fuse
6. Backup fuse (odometer)
7. Carburetor heater fuse
8. Spare fuse (x 4)
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Specified fuses:
Main fuse: 30 A
Backup fuse
(odometer): 5 A
Ignition fuse: 10 A
Headlight fuse: 15 A
Carburetor heater fuse 15 A
Signaling system fuse: 10 A

1. Screw (x 2)
2. Cowling
PERIODIC MAINTENANCE AND MINOR REPAIR
2
1
1
2
1
1
EAUB0013
Replacing the headlight and
auxiliary light bulb
This motorcycle is equipped with a quartz
bulb headlight. If the headlight bulb or aux-
iliary light bulb burns out, replace it as fol-
lows.
NOTE:
Skip steps 6-10 if only the headlight bulb is
being replaced. Skip steps 2-5 if only the
auxiliary light bulb is being replaced.1. Remove the headlight by removing
the screws, then tilt the cowling for-
ward.
2. Disconnect the headlight coupler and
the auxiliary light leads, and then re-
move the headlight bulb cover.
3. Remove the headlight bulb holder by
turning it counterclockwise, and then
remove the defective bulb.
EW000119WARNING0
Headlight bulbs get very hot. There-
fore, keep flammable products away
from a lit headlight bulb, and do not
touch the bulb until it has cooled down.
4. Place a new bulb into position, and
then secure it with the bulb holder.
EAU00462
6-29
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1. Headlight bulb cover
2. Auxiliary light bulb holder1. Headlight coupler

PERIODIC MAINTENANCE AND MINOR REPAIR
1
1
2
EC000105
Do not touch the glass part of the head-
light bulb to keep it free from oil, other-
wise the transparency of the glass, the
luminosity of the bulb, and the bulb life
will be adversely affected.
Thoroughly clean off any dirt and fin-
gerprints on the headlight bulb using a
cloth moistened with alcohol or thin-
ner.
CAUTION:5. Install the headlight bulb cover, and
then connect the coupler and auxil-
iary light leads.
6. Remove the socket (together with the
bulb) by turning it counterclockwise.
7. Remove the defective bulb by push-
ing it in and turning it counterclock-
wise.
8. Insert a new bulb into the socket,
push it in, and then turn it clockwise
until it stops.
9. Install the socket (together with the
bulb) by turning it clockwise.10. Connect the auxiliary light bulb leads.
11. Tilt the cowling back to the original
position, and then install the headlight
by installing the screws.
EAU00462
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1. Headlight bulb holder 1. Do not touch this area 1. Auxiliary light bulb holder
2. Auxiliary light bulb