so I removed the tube from my box last year when installing new stock filter. I first got the bike. put 4000 miles on it since. a few days ago I checked filter and it looked like it was doing its job. trapping lots of debris. florida is very sandy. cleaned the box. but during cleaning I noticed I never bothered to port the inlet to the box. looking at the inlet tube to throttle body I said to myself thats got to be a restriction. sure enough. taking tube out is step one. but the inlet needs to be ported out. bike picked up quite a bit of zip. very happy .
fast forward to tonight I am reading unrelated thread and the airbox discussion came up. removing tube allows air to bypass straight to the engine. I am thinking to myself, "no it cant be" I have been running bike for a year unfiltered. couldnt wait till morning to see if this was true. so I go outside to open box again. here is what I found.
so it is true. but there is a saving grace to it. the air filter still functions quite well as an air filter. I didnt clean the filter a few days ago. Only cleaned out the debris inside. those debris are all on the dirty side of filter. as it turns out air has mass to it. doest make right hand turns unless forced to. so the air still does go in to the cleaning side of filter first. not gonna go backwards any easier its easiest path is through the filter. add to the fact there is a fresh mist of oil coming from breather that is added to filter side. add to that the inlet to engine is high up in the box. the result to me is yeah , nothing heavy is gonna make into the engine. the lighter very small mostly just organic material making its way into engine doesnt hurt anything. it just burns at 1800 degrees combustion temps. it is known that even alloy shards will burn and not hurt your rings or cylinder walls. so I am officially relieved so much to the point I dont think I am going to add a dividing panel.
three days of filtering on plastic parts. 3500 miles on filter. only lightly shaken to banish the loose debris then put back in.