Page 15 of 98
DESCRIPTION
2-2
2
3
4
5
6
7
8
9
EAU10420
Right view
5 123
4
7
6
8
1. Grab bar (page 5-2)
2. Passenger seat (page 3-15)
3. Rider seat (page 3-15)
4. Coolant reservoir (page 6-17)
5. Radiator
6. Centerstand (page 6-29)
7. Air filter element (right) (page 6-19)
8. Shock absorber assembly spring preload adjusting ring (page 3-18)
Page 39 of 98
PRE-OPERATION CHECKS
4-2
2
3
45
6
7
8
9
EAU15605
Pre-operation check list
ITEM CHECKS PAGE
Fuel
Check fuel level in fuel tank.
Refuel if necessary.
Check fuel line for leakage.3-14
Engine oil
Check oil level in engine.
If necessary, add recommended oil to specified level.
Check vehicle for oil leakage.6-13
Final transmission oil
Check vehicle for oil leakage. 6-16
Coolant
Check coolant level in reservoir.
If necessary, add recommended coolant to specified level.
Check cooling system for leakage.6-17
Front brake
Check operation.
If soft or spongy, have Yamaha dealer bleed hydraulic system.
Check brake pads for wear.
Replace if necessary.
Check fluid level in reservoir.
If necessary, add recommended brake fluid to specified level.
Check hydraulic system for leakage.6-26
Rear brake
Check operation.
If soft or spongy, have Yamaha dealer bleed hydraulic system.
Check brake pads for wear.
Replace if necessary.
Check fluid level in reservoir.
If necessary, add recommended brake fluid to specified level.
Check hydraulic system for leakage.6-26
Throttle grip
Make sure that operation is smooth.
Check cable free play.
If necessary, have Yamaha dealer adjust cable free play and lubricate cable
and grip housing.6-22, 6-29
Page 62 of 98
PERIODIC MAINTENANCE AND MINOR REPAIR
6-18
1
2
3
4
5
6
7
8
9
3. Remove the coolant reservoir cov-
er by removing the screw.
4. Check the coolant level in the cool-
ant reservoir.
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:
ECA10471
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
1. Right floorboard mat
1. Screw
2. Coolant reservoir cover
1
1
2
1. Minimum level mark
2. Maximum level mark
3. Coolant reservoir cap
Coolant reservoir capacity (up to the
maximum level mark):
0.32 L (0.34 US qt) (0.28 Imp.qt)
1
2
3
Page 63 of 98
PERIODIC MAINTENANCE AND MINOR REPAIR
6-19
2
3
4
5
67
8
9 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
6-40 for further instructions.
EAU34204
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.
1. Screw
2. Air filter case cover
3. Rubber cap
1. Screw
2. Air filter case cover
3. Rubber cap
1
21
13
3
1
1
23
Page 85 of 98
PERIODIC MAINTENANCE AND MINOR REPAIR
6-41
2
3
4
5
67
8
9 Engine overheating
WARNING
EWAT1040
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.
Place a thick rag, like a towel, over the radiator cap, and then slowly rotate the cap counterclockwise to the de-
tent to allow any residual pressure to escape. When the hissing sound has stopped, press down on the cap
while turning it counterclockwise, and then remove the cap.
NOTE:
If coolant is not available, tap water can be temporarily used instead, provided that it is changed to the recommended coolant
as 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 NOTE.)
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.
Page 90 of 98
8-1
1
2
3
4
5
6
7
8
9
SPECIFICATIONS
EAU2633M
Dimensions:
Overall length:
2230 mm (87.8 in)
Overall width:
780 mm (30.7 in)
Overall height:
1380 mm (54.3 in)
Seat height:
760 mm (29.9 in)
Wheelbase:
1565 mm (61.6 in)
Ground clearance:
120 mm (4.72 in)
Minimum turning radius:
2600 mm (102.4 in)
Weight:
With oil and fuel:
YP400 219.0 kg (483 lb)
YP400A 223.0 kg (492 lb)
Engine:
Engine type:
Liquid cooled 4-stroke, DOHC
Cylinder arrangement:
Forward-inclined single cylinder
Displacement:
395.0 cm
3
Bore
×
stroke:
83.0
×
73.0 mm (3.27
×
2.87 in)
Compression ratio:
10.60 :1Starting system:
Electric starter
Lubrication system:
Wet sump
Engine oil:
Type:
SAE 10W-30, SAE 10W-40, SAE 15W-40,
SAE 20W-40 or SAE 20W-50
Recommended engine oil grade:
API service SG type or higher, JASO stan-
dard MA
Engine 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)
Final transmission oil:
Type:
SAE 10W-30 type SE motor oil
Quantity:
0.25 L (0.26 US qt) (0.22 Imp.qt)
Cooling system:
Coolant reservoir capacity (up to the maxi-
mum level mark):
0.32 L (0.34 US qt) (0.28 Imp.qt)
Radiator capacity (including all routes):
1.57 L (1.66 US qt) (1.38 Imp.qt)
Air filter:
Air filter element:
Oil-coated paper element
Fuel:
Recommended fuel:
Regular unleaded gasoline only
Fuel tank capacity:
14.0 L (3.70 US gal) (3.08 Imp.gal)
Fuel injection:
Throttle body:
Manufacturer:
AISAN
Spark plug (s):
Manufacturer/model:
NGK/CR7E
Spark plug gap:
0.7–0.8 mm (0.028–0.031 in)
Clutch:
Clutch type:
Dry, centrifugal automatic
Transmission:
Primary reduction system:
Helical gear
Primary reduction ratio:
31/14 (2.214)
Secondary reduction system:
Helical gear
-20 -10 0
10 20 30
40
50 ˚C
SAE 10W-30
SAE 15W-40SAE 20W-40SAE 20W-50
SAE 10W-40SAE 10W-50
