I noticed last season toward the end of summer that my fuel milage was dropping. This season I have adjusted the valves and removed the pair and added some extra air holes in my air breather, none of these things have helped with my terrable fuel milage if I had to say it has only gotten worse. I adjusted the valves once along with removing the pair and added new plugs, but had to do it again last week cause I set the rear valves to lose. I added extra air holes for cold air in duction, but like I said my fuel milage is getting worse...Any Ideas...? 2004 Volusia