Yamaha YFM80WP Owner's Manual page 267

NOTE:
The air filter element should be wet but not dripping.
8. Install the air filter element, the air filter
case cover and the front cover.
NOTE:
The air filter element should be cleaned every
20 – 40 hours. It should be cleaned and lubri-
cated more often if the machine is operated in
extremely dusty areas. Each time air filter ele-
ment maintenance is performed, check the air
inlet of the air 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 unfil-
tered air entering the engine.
cC
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, opera-
tion without the filter element will affect car-
buretor jetting with subsequent poor perfor-
mance and possible engine overheating.
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