Page 65 of 104

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
Page 66 of 104
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
Page 90 of 104

Periodic maintenance and adjustment
6-38
1
2
3
4
56
7
8
9
10
11
12 Engine overheating
WARNING
EWA10401
Do not remove the radiator cap when the engine and radiator are hot. Scalding hot fluid and steam may be
blown out under pressure, which could cause serious injury. Be sure to wait until the engine has cooled.
After removing the radiator cap retaining bolt, place a thick rag, like a towel, over the radiator cap, and then
slowly rotate the cap counterclockwise to the detent to allow any residual pressure to escape. When the hissingsound has stopped, press down on the cap while turning it counterclockwise, and then remove the cap.
TIPIf coolant is not available, tap water can be temporarily us
ed instead, provided that it is changed to the recommended coolantas soon as possible.
Wait until the
engine has cooled.
Check the coolant level in the
reservoir and radiator.
The coolant level
is OK.The coolant level is low.
Check the cooling system
for leakage.
Have a Yamaha dealer checkand repair the cooling system.Add coolant. (See TIP.)
Start the engine. If the engine overheats again,
have a
Yamaha dealer check
and repair the cooling system.
There is
leakage.
There is
no leakage.
UB90E2.book 38 ページ 2018年6月5日 火曜日 午後5時40分
Page 95 of 104

8-1
1
2
3
4
5
6
789
10
11
12
Specifications
EAU6999C
Dimensions:Overall length: 2075 mm (81.7 in)
Overall width: 815 mm (32.1 in)
Overall height: 1140 mm (44.9 in)
Seat height:
830 mm (32.7 in)
Wheelbase: 1440 mm (56.7 in)
Ground clearance: 135 mm (5.31 in)
Minimum turning radius:
3.0 m (9.84 ft)Weight:Curb weight:195 kg (430 lb)Engine:Combustion cycle:4-stroke
Cooling system: Liquid cooled
Valve train:
DOHC
Cylinder arrangement: Inline
Number of cylinders: 3-cylinder
Displacement:
847 cm
3
Bore stroke:
78.0 59.1 mm (3.07 2.33 in) Compression ratio:
11.5 : 1
Starting system:
Electric starter
Lubrication system: Wet sump
Engine oil:Recommended brand:
YAMALUBE
SAE viscosity grades: 10W-40
Recommended engine oil grade: API service SG type or higher, JASO stan-
dard MA
Engine 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)Coolant quantity:Coolant reservoir (up to the maximum 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)Air filter:Air filter element:
Oil-coated paper elementFuel:Recommended fuel:Premium unleaded gasoline (Gasohol
[E10] acceptable)
Fuel tank capacity: 14 L (3.7 US gal, 3.1 Imp.gal) Fuel reserve amount:
2.6 L (0.69 US gal, 0.57 Imp.gal)
Fuel injection:Throttle body:ID mark:
B901 00Spark plug(s):Manufacturer/model: NGK/CPR9EA9
Spark plug gap:
0.8–0.9 mm (0.031–0.035 in)Clutch:Clutch type:Wet, multiple-discDrivetrain:Primary reduction ratio:1.681 (79/47)
Final drive: Chain
Secondary reduction ratio:
2.813 (45/16)
Transmission type: Constant mesh 6-speed
Gear ratio: 1st:2.667 (40/15)
2nd: 2.000 (38/19)
3rd:
1.619 (34/21)
4th: 1.381 (29/21)
5th: 1.190 (25/21)
UB90E2.book 1 ページ 2018年6月5日 火曜日 午後5時40分