2003 YAMAHA YFM660R cooling

OPERATION ...........................................6-1
Starting a cold engine ..........................6-3
Starting a warm engine ........................6-9
Warming up ..........................................6-9
Reverse knob operation and
reverse driving ..................................6-11
Shifting ................................................6-15
To start out and accelerate: ...............6-17
To decelerate: ....................................6-21
Engine break-in ..................................6-23
Parking ...............................................6-27
Parking on a slope ..............................6-29
Accessories and loading ....................6-31
RIDING YOUR ATV..................................7-1
Getting to know your ATV .....................7-3
Ride with care and good judgement .....7-5
Be careful where you ride ...................7-27
Turning your ATV ................................7-39
Climbing uphill.....................................7-45
Riding downhill ....................................7-55
Crossing a slope .................................7-59
Crossing through shallow water ..........7-63
Riding over rough terrain ....................7-67
Sliding and skidding ............................7-69
What to do if .......................................7-73
What to do ..........................................7-73
67
PERIODIC MAINTENANCE AND
ADJUSTMENT ........................................ 8-1
Owner’s manual and tool kit ................. 8-3
Periodic maintenance/lubrication ......... 8-7
Panel removal and installation ........... 8-15
Engine oil and oil filter cartridge ......... 8-17
Cooling system ................................... 8-33
Changing the coolant.......................... 8-35
Spark plug inspection ......................... 8-43
Air filter element cleaning ................... 8-47
Carburetor adjustment ....................... 8-53
Idle speed adjustment ........................ 8-55
Throttle lever adjustment ................... 8-57
Valve clearance adjustment .............. 8-59
Front and rear brake pad inspection... 8-61
Brake fluid level inspection ................. 8-63
Brake fluid replacement ...................... 8-67
Front brake lever free play.................. 8-69
Brake pedal height adjustment ........... 8-71
Parking brake adjustment ................... 8-73
Adjusting the rear brake light switch ... 8-77
Clutch lever free play adjustment ...... 8-79
Drive chain slack check ...................... 8-81
Drive chain slack adjustment .............. 8-83
Lubricating the drive chain ................. 8-85
Cable inspection and lubrication ........ 8-89
8
U5LP62.book Page 2 Wednesday, May 8, 2002 11:24 AM

6-25
1. 0–10 hours:
Avoid continuous operation above half throt-
tle. Allow a cooling off period of five to ten
minutes after every hour of operation. Vary
the speed of the machine from time to time.
Do not operate it at one set throttle position.
2. 10–20 hours:
Avoid prolonged operation above 3/4 throttle.
Rev the machine freely through the gears but
do not use full throttle at any time.
3. After break-in:
Avoid prolonged full throttle operation. Vary
speeds occasionally.
U5LP62.book Page 25 Wednesday, May 8, 2002 11:24 AM

8-7
EBU00262
PERIODIC MAINTENANCE/LUBRICATION
ITEM ROUTINEINITIAL EVERY
1
month3
months6
months6
months1
year
Valves*•Check valve clearance.
•Adjust if necessary.
Cooling system•Check coolant leakage.
•Repair if necessary.
•Replace coolant every 24 months.Spark plug•Check condition.
•Adjust gap and clean.
•Replace if necessary.Air filter element•Clean.
•Replace if necessary.Every 20–40 hours
(More often in wet or dusty areas.)
Carburetor*•Check starter (choke) operation.
•Adjust engine idling speed.Crankcase breather
system*•Check breather hose for cracks or damage.
•Replace if necessary.Exhaust system*•Check for leakage.
•Tighten if necessary.
•Replace gasket if necessary.Fuel line*•Check fuel hose for cracks or damage.
•Replace if necessary.Engine oil
•Replace (Warm engine before draining.)Engine oil filter cartridge
•Replace if necessary.Drive chain
•Check and adjust slack/alignment/clean/lube.Front brake*•Check free play/operation/fluid leakage/
See NOTE Page 8-8.
•Correct if necessary.Rear brake*•Check operation/fluid leakage/See NOTE Page 8-8.
•Correct if necessary.Clutch*•Check operation.
•Adjust if necessary.U5LP62.book Page 7 Wednesday, May 8, 2002 11:24 AM

8-33 1. Coolant reservoir cap
2. Maximum level mark
3. Minimum level mark
1. Bouchon du vase d’expansion
2. Repère de niveau maximum
3. Repère de niveau minimum
1. Tapa del depósito de líquido refrigerante
2. Marca de nivel máximo
3. Marca de nivel mínimo
EBU01015
Cooling system
1. Check the coolant level in the coolant reser-
voir when the engine is cold as the coolant
level will vary with engine temperature. The
coolant level should be between the maxi-
mum and minimum marks.
2. If the level is low, remove the coolant reser-
voir cap, and then add coolant or distilled wa-
ter to raise it to the specified level.CAUTION:_ Hard water or salt water is harmful to the en-
gine. You may use soft water if you can’t get
distilled water. _NOTE:_

If water is added, have a Yamaha dealer
check the antifreeze content of the coolant as
soon as possible.


The radiator fan operation is completely auto-
matic. It is switched on or off according to the
coolant temperature in the radiator.
_If your ATV overheats, see page 8-124 for details.Coolant reservoir capacity:
0.29 L
U5LP62.book Page 33 Wednesday, May 8, 2002 11:24 AM

8-37 1. Coolant reservoir cap
2. Hose
1. Bouchon du vase d’expansion
2. Flexible
1. Tapa del depósito de refrigerante
2. Manguera
5. Remove the coolant reservoir cap.
6. Disconnect the hose on the coolant reservoir
side, and then drain the coolant from the
coolant reservoir.
7. After draining the coolant, thoroughly flush
the cooling system with clean tap water.
8. Replace the coolant drain bolt washer if it is
damaged, and then tighten the coolant drain
bolt to the specified torque.
9. Install the coolant reservoir hose.
10. Pour the recommended coolant into the radi-
ator until it is full.
11. Fill the coolant reservoir with coolant up to
the maximum level. Tightening torque:
Coolant drain bolt:
10 Nm (1.0 m·kgf)
U5LP62.book Page 37 Wednesday, May 8, 2002 11:24 AM

8-41
CAUTION:_ Hard water or salt water is harmful to the en-
gine. You may use soft water if you cannot get
distilled water. _12. Install the radiator cap and the coolant reser-
voir cap.
13. Start the engine and let it idle for several min-
utes. Stop the engine, and then check the
coolant level in the radiator. If it is low, add
more coolant until it reaches the top of the ra-
diator.
14. Check the coolant level in the reservoir. If it is
low, add coolant to the maximum level mark.
15. Start the engine and then check for coolant
leakage.NOTE:_ If any leakage is found, have a Yamaha dealer
check the cooling system. _16. Install the panel.
U5LP62.book Page 41 Wednesday, May 8, 2002 11:24 AM

8-124
Engine overheatingNOTE:If it is difficult to get the recommended coolant, tap water can be temporarily used, provided that it is
changed to the recommended coolant as soon as possible.
WARNING
Wait for the engine and radiator to cool before removing the radiator cap. You could be burned by
hot fluid and steam blown out under pressure. Always put a thick rag over the cap when opening.
Allow any remaining pressure to escape before completely removing the cap. Wait until the
engine has cooled.
Check the coolant level in the
reservoir tank and/or radiator.
Level is OK.Level is low, check the
cooling system for leakage.
No
leakage.Leakage.
Ask a Yamaha dealer to inspect
and repair the cooling system.Add coolant. (See NOTE.)
Restart the engine. If the engine overheats again, ask a
Yamaha dealer to inspect and/or repair the cooling system.
U5LP62.book Page 124 Wednesday, May 8, 2002 11:24 AM