2018 YAMAHA XMAX 125 check engine

Periodic maintenance and adjustment
7-8
7
EAU19623
Checking the spark plug
The spark plug is an important engine
component, which should be checked
periodically, preferably by a Yamaha
dealer. Since heat and deposits will
cause any spark plug to slowly erode,
it should be removed and checked in
accordance with the periodic mainte-
nance and lubrication chart. In addi-
tion, the condition of the spark plug
can reveal the condition of the engine.
The porcelain insulator around the
center electrode of the spark plug
should be a medium-to-light tan (the
ideal color when the vehicle is ridden
normally). If the spark plug shows a
distinctly different color, the engine
could be operating improperly. Do not
attempt to diagnose such problems
yourself. Instead, have a Yamaha deal-
er check the vehicle.
If the spark plug shows signs of elec-
trode erosion and excessive carbon or
other deposits, it should be replaced.
Before installing a spark plug, the
spark plug gap should be measured
with a wire thickness gauge and, if
necessary, adjusted to specification.Clean the surface of the spark plug
gasket and its mating surface, and
then wipe off any grime from the spark
plug threads.
TIP
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.
Specified spark plug:
NGK/CR9E
1. Spark plug gap
Spark plug gap:
0.7–0.8 mm (0.028–0.031 in)
Tightening torque:
Spark plug:
12.5 N·m (1.25 kgf·m, 9.22 lb·ft)
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Periodic maintenance and adjustment
7-9
7
EAUM3332
Engine oil
The engine oil level should be checked
before each ride. In addition, the oil
must be changed at the intervals spec-
ified in the periodic maintenance and
lubrication chart and when the service
indicator light comes on.
To check the engine oil level
1. Place the scooter on the center-
stand. 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 it
again to check the oil level.
TIP
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 drain bolt washer for
damage and replace it if neces-
sary.
1. Engine oil filler cap
2. Maximum level mark
3. Minimum level mark
1
3
2
1
ZAUM0685
1. Engine oil drain bolt
1. Engine oil drain bolt
2. Gasket
ZAUM11191
1
2
ZAUM0129
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Periodic maintenance and adjustment
7-10
7
TIP
Skip steps 5–9 if the oil filter element is
not being replaced.
5. Remove the oil filter element cover
by removing the bolts.
6. Remove the oil filter element and
O-ring.
7. Check the O-ring for damage and
replace it if necessary.
8. Install the new oil filter element
and an O-ring.
9. Install the oil filter element cover
by installing the bolts, then tight-
ening them to the specified
torque.TIP
Make sure that the O-ring is properly
seated.
10. Install the washer and the engine
oil drain bolt, and then tighten the
drain bolt to the specified torque.
TIP
Make sure that the washer is properly
seated.
11. Refill with the specified amount of
the recommended engine oil, and
then install and tighten the oil filler
cap.
TIP
Be sure to wipe off spilled oil on any
parts after the engine and exhaust sys-
tem have cooled down.
NOTICE
ECA11671
Do not use oils with a diesel
specification of “CD” or oils of a
higher quality than specified. In
1. Oil filter element cover
1. Oil filter element
2. O-ring
3. Oil filter element cover
ZAUM11201
1
2
3
ZAUM0712
Tightening torque:
Oil filter cover bolt:
10 N·m (1.0 kgf·m, 7.4 lb·ft)
Tightening torque:
Engine oil drain bolt:
20 N·m (2.0 kgf·m, 15 lb·ft)
Recommended engine oil:
See page 9-1.
Oil change quantity:
Without oil filter element replace-
ment:
1.40 L (1.48 US qt, 1.23 Imp.qt)
With oil filter removal:
1.50 L (1.59 US qt, 1.32 Imp.qt)
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Periodic maintenance and adjustment
7-11
7addition, do not use oils labeled
“ENERGY CONSERVING II” or
higher.
Be sure no foreign material en-
ters the crankcase.
12. 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.
13. Turn the engine off, and then
check the oil level and correct it if
necessary.
14. Reset the oil change indicator.
(See page 4-7.)
EAU20067
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 up the final
transmission oil by riding the
scooter for several minutes, 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 final transmission oil
filler cap and its O-ring from the fi-
nal transmission case.
5. Remove the final transmission oil
drain bolt and its gasket to drain
the oil from the final transmission
case.
1. Final transmission oil filler cap
2. O-ring
ZAUM1123
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Periodic maintenance and adjustment
7-12
7 6. Install the final transmission oil
drain bolt and its new gasket, and
then tighten the bolt to the speci-
fied torque.
7. Refill with the specified amount of
the recommended final transmis-
sion oil. WARNING! Make sure
that no foreign material enters
the final transmission case.
Make sure that no oil gets on
the tire or wheel.
[EWA11312]
8. Install the final transmission oil fill-
er cap and its new O-ring, and
then tighten the oil filler cap.
9. Check the final transmission case
for oil leakage. If oil is leaking,
check for the cause.
EAU20071
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.
EAU78580To check the coolant level
1. Place the vehicle on the center-
stand.
TIP
The coolant level must be
checked on a cold engine since
the level varies with engine tem-
perature.
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. Check the coolant level through
the check window.
TIP
The coolant should be between the
minimum and maximum level marks.
1. Final transmission oil drain bolt
Tightening torque:
Final transmission oil drain bolt:
20 N·m (2.0 kgf·m, 15 lb·ft)
Recommended final transmission
oil:
See page 9-1.
Oil quantity:
0.21 L (0.22 US qt, 0.18 Imp.qt)
ZAUM07031
1. Coolant level check window
2. Maximum level mark
3. Minimum level mark
1
2
3
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Periodic maintenance and adjustment
7-13
73. If the coolant is at or below the
minimum level mark, remove the
left floorboard mat by pulling it up.
4. Remove the coolant reservoir cov-
er.
5. Remove the coolant reservoir cap,
add coolant to the maximum level
mark, and then install the reservoir
cap. WARNING! Remove only
the coolant reservoir cap. Never
attempt to remove the radiator
cap when the engine is hot.
[EWA15162] NOTICE: 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 cooling system will notbe protected against frost and
corrosion. If water has been
added to the coolant, have a
Yamaha dealer check the anti-
freeze content of the coolant as
soon as possible, otherwise the
effectiveness of the coolant will
be reduced.
[ECA10473]
6. Install the coolant reservoir cover.
7. Place the left floorboard mat in the
original position and push it down-
ward to secure it.
EAU33032Changing the coolant
The coolant must be changed at the in-
tervals specified in the periodic mainte-
nance and lubrication chart. Have a
Yamaha dealer change the coolant.
WARNING! Never attempt to remove
the radiator cap when the engine is
hot.
[EWA10382]
1. Floorboard mat
1. Coolant reservoir cover
1
1
1. Coolant reservoir cap
Coolant reservoir capacity (up to
the maximum level mark):
0.18 L (0.19 US qt, 0.16 Imp.qt)
1
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Periodic maintenance and adjustment
7-15
73. Check the air filter element for
damage and replace it if neces-
sary.
4. Install the air filter element with the
colored side facing outward.
5. Install the V-belt case air filter cov-
ers by installing the screws.
NOTICE: Make sure that each
filter element is properly seated
in its case. The engine should
never be operated without the
filter elements installed, other-
wise the piston(s) and/or cylin-
der(s) may become excessively
worn.
[ECA10532]EAU21386
Checking the throttle grip free
play
Measure the throttle grip free play as
shown.
Periodically check the throttle grip free
play and, if necessary, have a Yamaha
dealer adjust it.
1. V-belt case air filter element
1
ZAUM0706
1. Throttle grip free play
Throttle grip free play:
3.0–5.0 mm (0.12–0.20 in)
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Periodic maintenance and adjustment
7-16
7
EAU21402
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.
EAU69760
Tires
Tires are the only contact between the
vehicle and the road. Safety in all con-
ditions of riding depends on a relatively
small area of road contact. Therefore, it
is essential to maintain the tires in good
condition at all times and replace them
at the appropriate time with the speci-
fied tires.
Tire air pressure
The tire air pressure should be
checked and, if necessary, adjusted
before each ride.
WARNING
EWA10504
Operation of this vehicle with im-
proper tire pressure may cause se-
vere injury or death from loss of
control.
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
adjusted in accordance with the
riding speed and with the total
weight of rider, passenger, car-
go, and accessories approved
for this model.
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