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Sorry but that's not correct. Yes when a filter gets more dirty it will become more restrictive, but the smaller the filter the more restriction before you even start. The same goes for any filter be it intake, crankcase breather, etc... People don't run bigger filters so that they don't have to clean them as often. They run bigger filters so that there is less restriction.
+1. Old school rule of thumb used to be that the air filter lid shouldn't be closer to the mouth of the carb than the bore of the carb. ie: if you have a 40mm Weber, the carb lib should be at *minimum* 40mm away from the mouth of the carb. It's all to do with pressure drops and airflow restriction. Short story: bigger is better when it comes to filtration.
I can imagine the maintenance required to keep a filter that small from blocking up too quickly ..and when it starts to clog up the airflow rate would drop dramatically. Which is why I went with the biggest damn filter I could find! :P