Briggs & Stratton 21000 Series Operating & Maintenance Instructions page 13

Air Cleaner
Check and clean the intake chamber for dirt. If the foam
air filter is dirty and worn, replace with clean filter.
1. Push cover tab to release cover, then pull cover
away from engine to service air filter.
Do not use pressurized air or solvents to clean
cartridge. Pressurized air can damage cartridge;
so vents w d sso ve cartr dge.
WARNING
Ensure air cleaner, retainer, and cover are
properly installed before starting engine.
Cover
Foam Air
Filter
Foam Air Filter
To clean wash in liquid detergent and water. Squeeze
dry in a clean cloth. Allow to dry thoroughly. Dip foam air
filter in clean engine oil, then squeeze out excess oil in
clean cloth. Engine will smoke if too much oil is left on
the filter.
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