Cutoff saws and other two-stroke tools that work in the dust will perform more consistently and powerfully if you know how to adjust their carburetors with changing filter condition. As the air filter accumulates dirt and the restriction reduces airflow, pressure in the carburetor's air inlet drops. The venturi in conventional carburetors compensates for reduced airflow by sucking more gas through the fuel jet.
The filter will eventually clog to the point that there's not enough air flowing to burn the fuel, but engine performance will suffer well before that point. Turning the needle valve on the carburetor to reduce fuel flow can often keep the engine running.