maintenance YAMAHA YFM660R 2003 User Guide

8-51 1. Hose
1. Flexible
1. Manguera
11. Install the air filter case cover and be sure to
connect the hose.
12. Install the seat.NOTE:_ The air filter element should be cleaned every 20–
40 hours. It should be cleaned and lubricated more
often if the machine is operated in extremely dusty
areas. Each time air filter element maintenance is
performed, check the air inlet to the air filter case
for obstructions. Check the air filter element rubber
joint to the carburetor and manifold fittings for an
airtight seal. Tighten all fittings securely to avoid
the possibility of unfiltered air entering the engine. _CAUTION:_ Never operate the engine with the air filter ele-
ment removed. This will allow unfiltered air to
enter, causing rapid engine wear and possible
engine damage. Additionally, operation with-
out the air filter element will affect carburetor
jetting with subsequent poor performance and
possible engine overheating. _
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8-53
EBU00296
Carburetor adjustment
The carburetor is a vital part of the engine and re-
quires very sophisticated adjustment. Most adjust-
ing should be left to a Yamaha dealer who has the
professional knowledge and experience to do so.
However, the idling speed may be performed by
the owner as a part of the usual maintenance rou-
tine.CAUTION:
The carburetor was set at the Yamaha factory
after many tests. If the settings are disturbed
by someone without sufficient technical
knowledge, poor engine performance and
damage may result.
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8-67

Brake fluid may deteriorate painted surfaces or
plastic parts. Always clean up spilled fluid im-
mediately.


Have a Yamaha dealer check the cause if the
brake fluid level goes down.
EBU01186
Brake fluid replacement
Complete fluid replacement should be done only
by trained Yamaha service personnel. Have a
Yamaha dealer replace the following components
during periodic maintenance or when they are
damaged or leaking.

Replace the oil seals every two years.


Replace the brake hoses every four years.
U5LP62.book Page 67 Wednesday, May 8, 2002 11:24 AM

8-85 1. O-rings
1. Joints toriques
1. Juntas tóricas
EBU00805
Lubricating the drive chain
The drive chain must be cleaned and lubricated at
the intervals specified in the periodic maintenance
and lubrication chart, otherwise it will quickly wear
out, especially when riding in dusty or wet areas. Ser-
vice the drive chain as follows.CAUTION:
The drive chain must be lubricated after wash-
ing the ATV or riding in the rain.1. Clean the drive chain with kerosene and a
small soft brush.CAUTION:
To prevent damaging the O-rings, do not clean
the drive chain with steam cleaners, high-pres-
sure washers or inappropriate solvents.
U5LP62.book Page 85 Wednesday, May 8, 2002 11:24 AM

8-105
EBU00385
Battery maintenance
1. When the machine is not used for a month or
longer, remove the battery and store it in a
cool, dark place. Completely recharge the
battery before reinstallation.CAUTION:
A special battery charger (constant volt-
age/ampere or constant voltage) is required for
recharging a sealed-type battery. Using a con-
ventional battery charger may shorten the bat-
tery life. 2. Always make sure the connections are cor-
rect when putting the battery back in the ma-
chine.
U5LP62.book Page 105 Wednesday, May 8, 2002 11:24 AM