power loss in flight

no good news.

installed new 350 dollar floats and flew for an hour with a single slight hesitation ten minutes into the flight, then ran great. a couple days later during take off had multiple hesitations and landed. changed fuel filter (old filter had some particulate matter in glass before filter) and started to check plugs to find what seemed like a not completely attached plug wire. re-attached plug wire and test flew with worst running yet. (Also the two plugs I looked at were white, does that mean there too lean ? does it tell that a certain passage is clogged or something ?). Next step is remove carbs and see if I can find anything blocking anything. Then the hard part, re-assembling everything. Wonder why airplanes, especially ones with such finicky carbs don't use marine style water/gas cartridge filters ? 

Any input appreciated.