you have to be careful as there are two diffent K&N kits, one of them is actually very good (edit but that could be the one for the 899)
Perhaps more important is the fact that it uses a very long length to reduce the bore of the induction pipe, so is probably less restrictive than most.
If you can take the filter out of it then fair play would be better than drilling. Just stick a tight over the end of it so no crap goes down the tube.
Obvioustly but in the OP they stated drilling holes in there airbox.. and let me think what happens when this is done hmmm.. it makes a louder noise when accelerator is applied plus lets all the sh!t in there engine brilliant!!
So instead of drilling holes and letting all the crap go in the holes just remove the filter and put your misses tight on the end atleast no crap is going to eventually *** up the engine.
Tights are not going to stop any of the fine material which damages an engine.
Dear God, this is a silly thread!
my way sounds the best remove the filter then put something on the end of it so it blocks the stuff from going in but also makes it suck in more air due to the filter being removed.
How about a DIY ram air duct connected to the original airbox?
Could be done crudely with plastic hose and a sawn off funnel positioned behind the o/s grille.