I understand the concept of the breather tube,and I cut it and rerouted it to the top of the cases(bracket for the carb tubes).I did this so it does not draw anthing in, just incase I were to take a fall in high sand or water.Also since the bike is moving forward no air would be pushed in because of the way the tube is routed. The pulses are pretty strong anyway pushing out I also know the pulses are short IN AND OUT,not really enough time to suck anything in. I know a few riders are running filters on the end of the tube in the airbox,I have a question on that. Since the breather tube draws in and pushes out on the stroke of the piston,I KNOW WE ARE TALKING VERY SHORT PULSES. Having a filter on the end of the tube,wouldn't that cause interference or unbalance especially on the up stroke of the piston,drawing in?. Especially if the filter is very dirty,the outgoing pulse is normal,but the incoming pulse is weaker because of the filter. Also if the filter is clogged and you have the outgoing pulse,I would think you have a great chance of blowing the cam cover gasket or internal seals. Also with a filter at the end ,I believe you will have some condensation inside the vent tube perhaps making it to the cam area. I feel pretty confident routing the tube a little higher like the cases and facing rearward with no filter.