Yamaha YXR660FAS Owner's Manual page 112

13. Install the console.
14. Install the seats.
NOTE:
_
The air filter element should be cleaned every
20–40 hours. It should be cleaned and lubri-
cated more often if the vehicle is operated in
extremely dusty areas. Each time air filter ele-
ment 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
element removed. This will allow unfiltered
air to enter, causing rapid engine wear and
possible engine damage. Additionally, op-
eration without the air filter element will af-
fect carburetor jetting with subsequent
poor performance and possible engine
overheating.
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