Yamaha BIGBEAR YFM400NM Owner's Manual page 122

CAUTION:
Do not twist the foam filter when
●
squeezing it.
● Do not add oil to the foam filter.
8. Inspect the foam cover. If damaged,
replace it.
9. Install the foam cover onto the air filter
element.
10. Install the air filter assembly and parts
removed for access.
1. Air filter element 2. Foam cover
NOTE:
The air filter element should be cleaned ev-
ery 20 ~ 40 hours. It should be cleaned
more often if the machine is operated in
extremely dusty areas. Each time filter ele-
ment maintenance is performed, check the
air inlet to the filter case for obstructions.
Check the air cleaner rubber joint to the
carburetor and manifold fittings for an air-
tight seal. Tighten all fittings securely to
avoid the possibility of unfiltered air enter-
ing the engine.
CAUTION:
Never operate the engine with the air filter
element removed. This will allow unfil-
tered air to enter, causing rapid engine
wear and possible engine damage. Addi-
tionally, operation without the filter ele-
ment will affect carburetor jetting with
subsequent poor performance and possi-
ble engine overheating.
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