Question.. I live a 5000 feet altitude in very DUSTY conditions, my DRZ runs rich (stock).. I was hoping not to re-jet the bike nor drill the air box. A mechanic at a local shop suggested put FMF Q4 slip on and a free flow drop in filter and the bike should lean out and run better with out rejetting. It makes sense logically, More air in more air out idea. Been riding for 30 + years not looking to make the bike too loud, as I am off road a bit and don't want to piss anyone off anymore. Thanks..