VM22 MIkuni Carburetor air filter comparison

Did a small engine air filter comparison on the Predator 212 with a Mikuni VM22 carburetor on the minibike. Tested a foam filter, and a cotton gauze filter, and a velocity stack with no filtration at all. I was surprised to find out that the cotton gauze filter didn't perform that well on this engine. The engine modifications include a billet rod and flywheel with a Mikuni carburetor and a header pipe.