Honda EP2500CX Owner's Manual page 38

SERVICING YOUR GENERATOR
5. Reinstall the foam air filter in the air cleaner case.
6. Set the hooks of the air cleaner cover to the setting pins securely,
then push the air cleaner cover to lock the latch tabs.
Be sure that the cover is set securely. There must be no clearance
between the air cleaner cover and case.
Operating the engine without an air filter or with a damaged air filter
will allow dirt to enter the engine, causing rapid engine wear. This type
of damage is not covered by the Distributor's Limited Warranty.
SETTING PIN
AIR CLEANER COVER
36
GOOD
HOOK
FORM AIR FILTER
NO GOOD
AIR CLEANER CASE
LATCH TAB