2004 YAMAHA BIG BEAR PRO 400 maintenance

8-45
9. Apply all-purpose grease to the air filter ele-
ment seat.
10. Install the air filter element on the frame.
11. Install the air filter element.
12. Install the air filter case cover by installing the
screws.
13. 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. _
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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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EBU11860
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.
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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 voltage/
ampere or constant voltage) is required for re-
charging a sealed-type battery. Using a con-
ventional battery charger may shorten the
battery life.2. Always make sure the connections are cor-
rect when putting the battery back in the ma-
chine.
U4SH6B.book Page 85 Tuesday, May 27, 2003 4:39 PM