Title should hint at what's going on lol. I decided to make some upgrades to my bike after having done nothing to it for the last 6 months I've owned it. I bought the yoshi slip on and a jet kit because it was recommended. I installed the slip on myself and rode around with that, without the new jetting for a few days. My MPG went right the hell out the window! So I asked my bro who knows a good deal about motors what the hell was going on. Long story short he says, "When you get your bike rejetted, your gas mileage will improve a litte because the air-fuel mix (don't remember his exact words) will match what your new exhaust is meant to have." SO, I get the new DynoJet installed at a dealer, and he basically told me that I'd actually have increasingly bad gas mileage with the new jet installed, regardless of the new pipe. Now... I literally just picked the bike up. I topped it off and have reset the tripometer, so I'll see exactly what's going down, but what's your guys' take on it? Should the DynoJet kit have improved the MPG, or worsened it after installing the new exhaust?