YAMAHA MAJESTY 400 2004 Workshop Manual

PERIODIC MAINTENANCE AND MINOR REPAIR
6-10
2
3
4
5
67
8
9

EAU34171
Checking the spark plug
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 mainte-
nance and lubrication chart. In addition,
the condition of the spark plug can re-
veal the condition of the engine.
To remove the spark plug
1. Open the rider seat. (See
page 3-13.)
2. Pull up the storage compartment
mat, and then remove the spark
plug cover by removing the
screws.3. Remove the spark plug cap.
4. Remove the spark plug as shown,
with the spark plug wrench includ-
ed in the owner’s tool kit.
To check the spark plug
1. Check that the porcelain insulator
around the center electrode of the
spark plug is a medium-to-light tan
(the ideal color when the vehicle is
ridden normally).
NOTE:

If the 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.
2. Check the spark plug for electrode
erosion and excessive carbon or
other deposits, and replace it if
1. Storage compartment mat
2. Spark plug cover
3. Screw
1. Spark plug cap
1
2
3(×3)
1

1. Spark plug wrench
1

PERIODIC MAINTENANCE AND MINOR REPAIR
6-11
1
2
3
4
5
6
7
8
9
necessary.
To install the 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 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 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.
NOTE:

Make sure the spark plug wire is fas-
tened in the clamp as shown.5. Install the spark plug cover by in-
stalling the screws.
6. Place the storage compartment
mat in the original position.
7. Close the rider seat. Specified spark plug:
NGK/CR7E
1. Spark plug gap
Spark plug gap:
0.7–0.8 mm (0.028–0.031 in)
1

Tightening torque:
Spark plug:
12.5 Nm (1.25 m·kgf, 9 ft·lbf)
1. Spark plug cap
2. Spark plug wire clamp
1
2

PERIODIC MAINTENANCE AND MINOR REPAIR
6-12
2
3
4
5
67
8
9

EAU34181
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 and when the oil change in-
dicator comes on.
To check the engine oil level
1. Place the vehicle on the center-
stand.
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, remove the oil filler cap, wipe
the dipstick clean, insert it back
into the oil filler hole (without
screwing it in), and then remove itagain to check the oil level.
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.
5. Insert the dipstick into the oil filler
hole, and then tighten the oil filler
cap.
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 engine
to collect the used oil.
3. Remove the engine oil filler cap
and the engine oil drain bolt to
drain the oil from the crankcase.
4. Check the washer for damage and
replace it if necessary.
1. Engine oil filler cap
2. Maximum level mark
3. Minimum level mark
1
2
3
1

1. Engine oil drain bolt
1

PERIODIC MAINTENANCE AND MINOR REPAIR
6-13
1
2
3
4
5
6
7
8
9
NOTE:

Skip steps 5–7 if the oil filter element is
not being replaced.
5. Remove the oil filter element cover
by removing the bolts.6. Remove and replace the oil filter
element and O-rings.
CAUTION:

ECA12910
When removing the oil filter element
cover, the compression spring will
fall out. Take care not to lose the
compression spring.
7. Install the compression spring and
oil filter element cover by installing
the bolts, then tightening them to
the specified torque.
1. Engine oil drain bolt
2. Washer
2
1

1. Bolt
2. Oil filter element cover
21
(×3)

1. Oil filter element cover
2. O-ring
3. Compression spring
4. Oil filter element
1
2
3
4

PERIODIC MAINTENANCE AND MINOR REPAIR
6-14
2
3
4
5
67
8
9
NOTE:

Make sure that the O-rings are properly
seated.
8. Install the washer and the engine
oil drain bolt, and then tighten the
drain bolt to the specified torque.
NOTE:

Make sure that the washer is properly
seated.
9. Add the specified amount of the
recommended engine oil, and then
install and tighten the oil filler cap.
CAUTION:

ECA11670

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.

Be sure no foreign material en-
ters the crankcase.
10. Start the engine, and then let it idle
for several minutes while checking
it for oil leakage. If oil is leaking, im-
mediately turn the engine off and
check for the cause.11. Reset the oil change indicator ac-
cording to the following procedure.
To reset the oil change indicator
1. Turn the key to “ON”.
2. Hold the “OIL CHANGE” button
pushed for two to eight seconds.
3. Release the “OIL CHANGE” but-
ton, and the oil change indicator
will go off.
NOTE:

If the engine oil is changed before the
oil change indicator comes on (i.e. be-
fore the periodic oil change interval has
been reached), the indicator must be
reset after the oil change for the next
periodic oil change to be indicated at
Tightening torque:
Oil filter element cover bolt:
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Tightening torque:
Engine oil drain bolt:
20 Nm (2.0 m·kgf, 14.5 ft·lbf)
Recommended engine oil:
See page 8-1.
Oil quantity:
Without oil filter element
replacement:
1.50 L (1.59 US qt)
(1.32 Imp.qt)
With oil filter element
replacement:
1.70 L (1.80 US qt)
(1.50 Imp.qt)

1. “OIL CHANGE” button
1

PERIODIC MAINTENANCE AND MINOR REPAIR
6-15
1
2
3
4
5
6
7
8
9
the correct time. To reset the oil change
indicator before the periodic oil change
interval has been reached, follow the
above procedure, but note that the indi-
cator will come on for 1.4 seconds after
releasing the “OIL CHANGE” button,

otherwise repeat the procedure.
EAU20060
Final transmission oil
The final transmission case must be
checked for oil leakage before each
ride. If any leakage is found, have a
Yamaha dealer check and repair the
scooter. In addition, the final transmis-
sion oil must be changed as follows at
the intervals specified in the periodic
maintenance and lubrication chart.
1. Start the engine, warm it up by
riding the scooter for several min-
utes, and then stop the engine.
2. Place the scooter on the center-
stand.
3. Place an oil pan under the final
transmission case to collect the
used oil.
4. Remove the oil filler cap and drain
bolt to drain the oil from the final
transmission case.5. Install the final transmission oil
drain bolt, and then tighten it to the
specified torque.
6. Add the specified amount of the
recommended final transmission
oil, and then install and tighten the
oil filler cap.
1. Final transmission oil filler cap
2. Final transmission oil drain bolt
Tightening torque:
Final transmission oil drain bolt:
22 Nm (2.2 m·kgf, 15.9 ft·lbf)
2
1

PERIODIC MAINTENANCE AND MINOR REPAIR
6-16
2
3
4
5
67
8
9
WARNING

EWA11310

Make sure that no foreign mate-
rial enters the final transmission
case.

Make sure that no oil gets on the
tire or wheel.
7. Check the final transmission case
for oil leakage. If oil is leaking,
check for the cause.
EAU20070
Coolant
The coolant level should be checked
before each ride. In addition, the cool-
ant must be changed at the intervals
specified in the periodic maintenance
and lubrication chart.
EAU34191
To check the coolant level
1. Place the vehicle on a level sur-
face and hold it in an upright posi-
tion.
NOTE:


The coolant level must be checked
on a cold engine since the level
varies with engine temperature.

Make sure that the vehicle is posi-
tioned straight up when checking
the coolant level. A slight tilt to the
side can result in a false reading.
2. Pull up the right floorboard mat as
shown.3. Remove the coolant reservoir cov-
er by removing the screw.
4. Check the coolant level in the cool-
ant reservoir. Recommended final transmis-
sion oil:
See page 8-1.
Oil quantity:
0.25 L (0.26 US qt)
(0.22 Imp.qt)
1. Right floorboard mat
1. Screw
2. Coolant reservoir cover
1
1
2

PERIODIC MAINTENANCE AND MINOR REPAIR
6-17
1
2
3
4
5
6
7
8
9
NOTE:

The coolant should be between the
minimum and maximum level marks.
5. If the coolant is at or below the
minimum level mark, open the
coolant reservoir cap, add coolant
to the maximum level mark, and
then close the coolant reservoir
cap.
CAUTION:

ECA10470

If coolant is not available, use
distilled water or soft tap water
instead. Do not use hard water
or salt water since it is harmful
to the engine.

If water has been used instead
of coolant, replace it with cool-
ant as soon as possible, other-
wise the engine may not be
sufficiently cooled and the cool-
ing system will not be protected
against frost and corrosion.

If water has been added to the
coolant, have a Yamaha dealer
check the antifreeze content of
the coolant as soon as possible,
otherwise the effectiveness of
the coolant will be reduced.
WARNING

EWA10380
Never attempt to remove the radiator
cap when the engine is hot.
6. Install the coolant reservoir cover
by installing the screw.
7. Place the right floorboard mat in
the original position.
NOTE:


The radiator fan is automatically
switched on or off according to the
coolant temperature in the radia-
tor.

If the engine overheats, see page
6-37 for further instructions.
1. Minimum level mark
2. Maximum level mark
3. Coolant reservoir cap
1
2
3

Coolant reservoir capacity (up to
the maximum level mark):
0.32 L (0.34 US qt)
(0.28 Imp.qt)

PERIODIC MAINTENANCE AND MINOR REPAIR
6-18
2
3
4
5
67
8
9

EAU34203
Air filter elements and check
hoses and V-belt case air filter
element
The air filter elements and the V-belt
case air filter element should be ser-
viced at the intervals specified in the
periodic maintenance and lubrication
chart. Service all air filter elements
more frequently if you are riding in un-
usually wet or dusty areas.
Replacing the air filter elements
1. Place the scooter on the center-
stand.
NOTE:

Continue as follows for each air filter el-
ement.
2. Remove the air filter case cover by
removing the rubber cap and
screws.
Left
Right
3. Pull the air filter element out.
Left
Right
4. Insert a new air filter element into
the air filter case.
5. Install the air filter case cover by in-
stalling the screws.
6. Install the rubber cap.

1. Screw
2. Air filter case cover
3. Rubber cap
1. Screw
2. Air filter case cover
3. Rubber cap
1(×6)
21
13
3
1(×5)
1
23

1. Air filter element
1. Air filter element
1
1

PERIODIC MAINTENANCE AND MINOR REPAIR
6-19
1
2
3
4
5
6
7
8
9
CAUTION:

ECA12922

Make sure that each filter ele-
ment is properly seated in its
case.

Always replace both air filter el-
ements at the same time, other-
wise poor engine performance
or damage to the engine may re-
sult.

The engine should never be op-
erated without the filter ele-
ments installed, otherwise the
piston(s) and/or cylinder(s) may
become excessively worn.
To clean the air filter check hoses
1. Check the hose at the bottom of
both air filter cases for accumulat-
ed dirt or water.
Left
Right
2. If dirt or water is visible, remove
the hose, clean it, and then install
it.
Cleaning the V-belt case air filter el-
ement
1. Remove cowling E. (See
page 6-6.)
2. Remove panel B. (See page 6-6.)
3. Remove the V-belt air filter case
cover by removing the screws.
4. Remove the V-belt case air filter
element by removing the screws.

1. Air filter check hose
1. Air filter check hose
1
1

1. Screw
2. V-belt air filter case cover
2
11(×5)1