Yamaha RHINO 660 YXR660FAT Manuel Du Propriétaire page 310

NOTE:
_
The air filter element should be cleaned every 20–
40 hours. It should be cleaned and lubricated more
often if the vehicle 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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