I picked up a new oil filter for my 520 exc. It is a foam unit that requires oiling. I placed the filter in a gallon ziplock bag and proceeded to pour a pint of air filter oil into the bag. I realize that you are supposed to squeeze out the "excess" oil, but how much constitutes excess? Is there a rule of thumb for how much oil should be consumed in oiling a foam filter? Also, has anyone else used the ziplock bag oiling method? This seems like a good idea in that it keeps my fingers clean. Anyone got any reasons why this is a bad idea?