Periodic maintenance and adjustment
6-9
1
2
3
4
567
8
9
10
11
12
EAU19653
Checking the spark plugsThe spark plugs are important engine
components, which should be checked
periodically, preferably by a Yamaha
dealer. Since heat and deposits will
cause any spark plug to slowly erode,
they 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.
The porcelain insulator around the cen-
ter electrode of each spark plug should
be a medium-to-light tan (the ideal color
when the vehicle is ridden normally),
and all spark plugs installed in the en-
gine should have the same color. If any
spark plug shows a distinctly different
color, the engine could be operating im-
properly. Do not attempt to diagnose
such problems yourself. Instead, have
a Yamaha dealer check the vehicle.
If a spark plug shows signs of electrode
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.
TIPIf a torque wrench is not available wheninstalling 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.NOTICE
ECA10841
Do not use any tools to remove or in-
stall the spark plug cap, otherwise
the ignition coil coupler may get
damaged. The spark plug cap may
be difficult to remove because the
rubber seal on the end of the cap fits
tightly. To remove the spark plug
cap, simply twist it back and forth
while pulling it out; to install it, twistit back and forth while pushing it in.
Specified spark plug:
NGK/CPR9EA9
1. Spark plug gapSpark plug gap:0.8–0.9 mm (0.031–0.035 in)
Tightening torque: Spark plug:13 N·m (1.3 kgf·m, 9.6 lb·ft)
UB90E2.book 9 ページ 2018年6月5日 火曜日 午後5時40分
Periodic maintenance and adjustment
6-10
1
2
3
4
56
7
8
9
10
11
12
EAU36112
CanisterThis model is equipped with a canister
to prevent the discharging of fuel vapor
into the atmosphere. Before operating
this vehicle, make sure to check the fol-
lowing:
Check each hose connection.
Check each hose and canister for
cracks or damage. Replace if dam-
aged.
Make sure that the canister breath-
er is not blocked, and if necessary,
clean it.
EAU1990D
Engine oilThe engine oil level should be checked
regularly. In addition, the oil must be
changed and the oil filter cartridge re-
placed at the intervals specified in the
periodic maintenance chart.NOTICE
ECA11621
In order to prevent clutch slip-
page (since the engine oil also
lubricates the clutch), do not
mix any chemical additives. Do
not use oils with a diesel speci-
fication of “CD” or oils of a high-
er quality than specified. In
addition, do not use oils labeled
“ENERGY CONSERVING II” or
higher.
Make sure that no foreign mate-rial enters the crankcase. To check the engine oil level
1. After warming up the engine, wait a few minutes for the oil to settle.
2. With the vehicle on a level surface, hold it upright for an accurate read-
ing.
3. Look at the check window located at the bottom-right side of the
crankcase.
TIPThe engine oil should be between theminimum and maximum level marks.
4. If the engine oil is at or below the minimum level mark, remove the
1. Canister
2. Canister breather hose
1
2
Recommended engine oil: See page 8-1.
Oil quantity: Oil change:2.40 L (2.54 US qt, 2.11 Imp.qt)
With oil filter removal: 2.70 L (2.85 US qt, 2.38 Imp.qt)
1. Engine oil filler cap
2. Engine oil level check window
3. Maximum level mark
4. Minimum level mark
1
2
34
UB90E2.book 10 ページ 2018年6月5日 火曜日 午後5時40分
Periodic maintenance and adjustment6-11
1
2
3
4
567
8
9
10
11
12
oil filler cap and add oil.
5. Check the engine oil filler cap O-ring. Replace if damaged.
6. Install the engine oil filler cap.
To change the engine oil (and filter) 1. Start the engine, warm it up briefly, 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 then the engine oil drain bolt
and gasket.
TIPSkip steps 4–6 if the oil filter cartridge isnot being replaced.
4. Remove the oil filter cartridge with an oil filter wrench.
TIPAn oil filter wrench is available at aYamaha dealer.
5. Apply a thin coat of clean engine oil to the O-ring of the new oil filter
cartridge.
1. Engine oil filler cap
2. O-ring
21
1. Engine oil drain bolt
2. Gasket
21
1. Oil filter wrench
2. Oil filter cartridge
2
1
UB90E2.book 11 ページ 2018年6月5日 火曜日 午後5時40分
Periodic maintenance and adjustment
6-12
1
2
3
4
56
7
8
9
10
11
12
TIPMake sure that the O-ring is properlyseated. 6. Install the new oil filter cartridge, and then tighten to the specified
torque. 7. Install the engine oil drain bolt with
a new gasket, and then tighten the
bolt to the specified torque.
8. Pour the specified amount of the recommended oil into the crank-
case.
TIPUsing a funnel is recommended.
9. After checking the engine oil filler cap O-ring, install the filler cap.TIPWipe off any spilled oil before startingthe engine.
10. Start the engine and let it idle for several minutes while checking for
oil leaks. If any leakage is found,
immediately stop the engine and
check for the cause.
NOTICE
ECA10402
If the oil level warning light flickers
or remains on even if the oil level is
correct, immediately turn the engine
off and have a Yamaha dealer checkthe vehicle.
11. Turn the engine off, wait a few min- utes until the oil settles, and then
check the oil level one last time.
1. O-ring
1. Torque wrench
1
Tightening torque:Oil filter cartridge:17 N·m (1.7 kgf·m, 13 lb·ft)
Tightening torque: Engine oil drain bolt:43 N·m (4.3 kgf·m, 32 lb·ft)
UB90E2.book 12 ページ 2018年6月5日 火曜日 午後5時40分
Periodic maintenance and adjustment6-13
1
2
3
4
567
8
9
10
11
12
EAUS1203
CoolantThe coolant level should be checked
regularly. In addition, the coolant must
be changed at the intervals specified in
the periodic maintenance chart.TIPIf genuine Yamaha coolant is not avail-
able, use an ethylene glycol antifreeze
containing corrosion inhibitors for alu-
minum engines and mix with distilledwater at a 1:1 ratio.
EAU20097
To check the coolant level
Since the coolant level varies with en-
gine temperature, check when the en-
gine is cold. 1. Park the vehicle on a level surface.
2. With the vehicle in an upright posi- tion, look at the coolant level in the reservoir.
3. If the coolant is at or below the minimum level mark, remove the
coolant reservoir cap. WARNING!
Remove only the coolant reser-
voir cap. Never attempt to re-
move the radiator cap when the
engine is hot.
[EWA15162]
4. Add coolant to the maximum level mark. 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 not
be 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
Recommended coolant: YAMALUBE coolant
Coolant quantity: Coolant reservoir (max level mark): 0.25 L (0.26 US qt, 0.22 Imp.qt)
Radiator (including all routes): 1.93 L (2.04 US qt, 1.70 Imp.qt)
1. Coolant reservoir
2. Maximum level mark
3. Minimum level mark
21
3
1. Coolant reservoir cap
1
UB90E2.book 13 ページ 2018年6月5日 火曜日 午後5時40分
Periodic maintenance and adjustment
6-14
1
2
3
4
56
7
8
9
10
11
12 be reduced.
[ECA10473]
5. Install the coolant reservoir cap.
EAU33032
Changing 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]
EAU36765
Air filter elementThe air filter element must be replaced
at the intervals specified in the periodic
maintenance and lubrication chart.
Have a Yamaha dealer replace the air
filter element.
EAU44735
Checking the engine idling
speedCheck the engine idling speed and, if
necessary, have it corrected by a
Yamaha dealer.Engine idling speed:
1100–1300 r/min
UB90E2.book 14 ページ 2018年6月5日 火曜日 午後5時40分
Periodic maintenance and adjustment6-15
1
2
3
4
567
8
9
10
11
12
EAU21386
Checking the throttle grip free
playMeasure the throttle grip free play as
shown.
Periodically check the throttle grip free
play and, if necessary, have a Yamaha
dealer adjust it.
EAU21403
Valve clearanceThe valves are an important engine
component, and since valve clearance
changes with use, they must be
checked and adjusted at the intervals
specified in the periodic maintenance
chart. Unadjusted valves can result in
improper air-fuel mixture, engine noise,
and eventually engine damage. To pre-
vent this from occurring, have your
Yamaha dealer check and adjust the
valve clearance at regular intervals.TIPThis service must be performed whenthe engine is cold.
EAU64410
TiresTires 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 ad-
justed in accordance with the
riding speed and with the total
1. Throttle grip free playThrottle grip free play: 3.0–5.0 mm (0.12–0.20 in)
1
UB90E2.book 15 ページ 2018年6月5日 火曜日 午後5時40分
Periodic maintenance and adjustment
6-22
1
2
3
4
56
7
8
9
10
11
12
EAU22734
Changing the brake fluidHave a Yamaha dealer change the
brake fluid every 2 years. In addition,
have the seals of the master cylinders
and brake calipers, as well as the brake
hoses replaced at the intervals listed
below or sooner if they are damaged or
leaking.
Brake seals: every 2 years
Brake hoses: every 4 years
EAU22762
Drive chain slackThe drive chain slack should be
checked before each ride and adjusted
if necessary.
EAU2277G
To check the drive chain slack 1. Place the motorcycle on the sides- tand.TIPWhen checking and adjusting the drive
chain slack, there should be no weighton the motorcycle.
2. Shift the transmission into the neu- tral position.
3. Measure the drive chain slack as shown. 4. If the drive chain slack is incorrect,
adjust it as follows. NOTICE: Im-
proper drive chain slack will
overload the engine as well as
other vital parts of the motorcy-
cle and can lead to chain slip-
page or breakage. If the drive
chain slack is more than 25.0
mm (0.98 in), the chain can dam-
age the frame, swingarm, and
other parts. To prevent this from
occurring, keep the drive chain
slack within the specified lim-
its.
[ECA17791]
1. Drive chain slackDrive chain slack: 5.0–15.0 mm (0.20–0.59 in)
1
UB90E2.book 22 ページ 2018年6月5日 火曜日 午後5時40分