I got a new motor from Murrey, KY a few years ago. The first time I cranked it with the air filter on, no problem. Ran it until it was out of gas. Let it cool and refilled with gas, wouldn't crank. I removed the air filter and it cranked. Replaced air filter and ran it until out of gas again. Let it cool, refilled with gas, washed air filter, wouldn't crank. Removed air filter and it cranked. Replaced air filter and ran it until out of gas. Bought a new air filter, installed it, wouldn't crank. Remove air filter and it cranks. Wasted $29 on a new air filter.