FYI: There's an "Edit" button in the lower right of your posts
That's not what you said previously

That changes everything...
The air filter is designed to restrict air entering the engine, the dirtier it gets, the more air it restricts &, in most cases, the carb settings are adjusted to suit...
When you remove the air filter, you remove the restriction, hence, more air is allowed to enter the engine which drastically alters the air/fuel mixture; lot's more but no more fuel = a severely lean condition & the engine will not run; even when you refit the clogged air filter, the engine still needs to recover from not having enough fuel to run so, prime it a few times &/or try starting it with the choke on...