10. Grab bar
11. Main fuse (page 6-31)
12. Battery (page 6-30)
13. Rear brake fluid reservoir (page 6-22)14. Coolant reservoir (page 6-12) 15. Front brake fluid reservoir (page 6-22)
16. Coolant drain bolt (page 6-12)
17. Engine oil filter element (page 6-10)
18. Brake pedal (page 3-11)
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DESCRIPTION
EAU10420Right view
2-2
XT660Z 01-03 ING 10-03-2008 16:11 Pagina 13
PRE-OPERATION CHECKS
4-2
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ITEM
Fuel
Engine oil
Coolant
Front brake
Rear brake
EAU15605
Pre-operation check list
CHECKS
• Check fuel level in fuel tank.
• Refuel if necessary.
• Check fuel line for leakage.
• Check oil level in oil tank.
• If necessary, add recommended oil to specified level.
• Check vehicle for oil leakage.
• Check coolant level in reservoir.
• If necessary, add recommended coolant to specified level.
• Check cooling system for leakage.
• 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.
• 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. PAGE
3-12
6-9
6-12
3-11, 6-21, 6-22, 6-26
3-11, 6-21, 6-22, 6-27
XT660Z 04-06 ING 11-03-2008 8:30 Pagina 2
PERIODIC MAINTENANCE AND MINOR REPAIR
6-12
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EAU20070
Coolant
The coolant level should be checked
before each ride. In addition, the
coolant must be changed at the inter-
vals specified in the periodic mainte-
nance and lubrication chart.
EAU20252
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 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 in the coolant reservoir.
ECA11620CAUTION:
● 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
higher quality than specified. In
addition, do not use oils la-
beled “ENERGY CONSERVING
II” or higher.
● Make sure that no foreign ma-
terial enters the crankcase.
14. Start the engine, and then let it idle for several minutes while
checking it for oil leakage. If oil is
leaking, immediately turn the en-
gine off and check for the cause.
15. Turn the engine off, and then check the oil level and correct it if
necessary.
16. Install the engine guard by in- stalling the screws.
NOTE:
Be sure to wipe off spilled oil on any
parts after the engine and exhaust
system have cooled down.
Recommended engine oil:See page 8-1.
Oil quantity: Without oil filter element
replacement:2.50 L (2.64 US qt) (2.19 Imp.qt)
With oil filter element replacement: 2.60 L (2.73 US qt) (2.26 Imp.qt)
ECAM1060CAUTION:
The engine oil tank must be filled in
2 steps. First, fill the engine oil tank
with 1.90 L (2.0 US qt) (1.67 Imp.qt)
of the recommended engine oil.
Then, start the engine, race it 5 or 6
times, turn it off, and then add the
remainder of the engine oil.
XT660Z 04-06 ING 11-03-2008 8:31 Pagina 6-12
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-13
NOTE:
The coolant should be between the
minimum and maximum level marks.
1. Coolant reservoir
2. Maximum level mark
3. Minimum level mark
4. Reservoir cap
3. If the coolant is at or below theminimum level mark, remove pan-
el E (See page 6-7.), remove the
reservoir cap, add coolant to the
maximum level mark, and then in-
stall the reservoir cap and the
panel.
ECA10471CAUTION:
● 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
coolant as soon as possible,
otherwise 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 antifreeze content of
the coolant as soon as possi-
ble, otherwise the effective-
ness of the coolant will be re-
duced.
Coolant reservoir capacity:
0.50 L (0.52 US qt) (0.44 Imp.qt)
EWA10380
WARNING0
Never attempt to remove the radia-
tor cap when the engine is hot.
NOTE:
●The radiator fan is automatically
switched on or off according to
the coolant temperature in the ra-
diator.
●If the engine overheats, see page
3-4 for further instructions.
EAU33030
Changing the coolant
EWA10380
WARNING0
Never attempt to remove the radia-
tor cap when the engine is hot.
The coolant must be changed at the
intervals specified in the periodic
maintenance and lubrication chart.
Have a Yamaha dealer change the
coolant.
XT660Z 04-06 ING 11-03-2008 8:31 Pagina 6-13
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-41
Engine overheatingEWA10400
WARNING0
●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, a\
nd then
slowly rotate the cap counterclockwise to the detent to allow any residual pressure to escape. When the hiss-
ing 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 low.
Check the cooling
system for leakage.
The coolant level
is OK.
There is
leakage.
There is no
leakage.
Have a Yamaha dealer check
and repair the cooling system.
Start the engine. If the engine overheats again, have
a Yamaha dealer check and repair the cooling system.
Add coolant. (See NOTE.)
XT660Z 04-06 ING 11-03-2008 8:31 Pagina 6-41
SPECIFICATIONS
8-1
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Engine oil:Type: SAE10W30 or SAE10W40 or SAE15W40
or SAE20W40 or SAE20W50
Recommended engine oil grade: API service SE, SF, SG type or higher
Engine oil quantity: Without oil filter element replacement:2.50 L (2.64 US qt) (2.19 Imp.qt)
With oil filter element replacement: 2.60 L (2.73 US qt) (2.26 Imp.qt)
Total amount (dry engine): 2.90 L (3.07 US qt) (2.55 Imp.qt)
Cooling system:Radiator capacity (including all routes): 1.2 L (1.26 US qt) (1.05 Imp.qt) (Radiator) +
0.5 L (0.52 US qt) (0.44 Imp.qt)
(Coolant reservoir)
Coolant reservoir capacity (up to the
maximum level mark): 0.50 L (0.52 US qt) (0.44 Imp.qt)
From low to full level: 0.30 L (0.32 US qt) (0.26 Imp.qt)
Air filter:Air filter element:Paper
Fuel:Recommended fuel:Premium unleaded gasoline only
Fuel tank capacity: 23.0 L (6.07 US gal) (5.06 Imp.gal)
Fuel reserve amount: 6.7 L (1.76 US gal) (1.46 Imp.gal)
Fuel injection:Manufacturer:DENSO
Model: 297500-0390
Spark plug:Manufacturer/model:NGK/CR7EGap:0.7-0.8 mm (0.028-0.032 in)
Clutch:Clutch type:Wet, multiple-disc
Transmission:Primary reduction system:Spur gear
Primary reduction ratio: 75/36 (2.083)
Secondary reduction system: Chain drive
Secondary reduction ratio: 45/15 (3.00)
Transmission type: Constant mesh 5-speed
Dimensions:Overall length:2246 mm (88.42 in)
Overall width: 864 mm (34.01 in)
Overall height: 1477 mm (58.14 in)
Seat height: 896 mm (35.27 in)
Wheelbase: 1500 mm (59.05 in)
Ground clearance: 260 mm (10.23 in)
Minimum turning radius: 1958 mm (77.08 in)
Basic weight:With oil and fuel:208.5 kg (459 lb)
Engine:Engine type:Liquid cooled 4-stroke, SOHC
Cylinder arrangement: Forward-inclined single cylinder
Displacement: 660.0 cm
3(40.27 cu.in)
Bore x stroke: 100.0 x 84.0 mm (3.94 x 3.31 in)
Compression ratio: 10.00 : 1
Starting system: Electric starter
Lubrication system: Dry sump
-20 -10 0 10 20 30 40 50 °C
SAE 10W-30
SAE 10W-40
SAE 20W-40
SAE 20W-50
SAE 15W-40
XT660Z 07-10 ING 11-03-2008 8:33 Pagina 6