So my YFZ has been driving me nuts for the past 6 months. I had it dyno tuned and immediately after the tune I swapped out all the plastics. Now it misfires when you get to around 1/2-3/4 throttle. Its possible the problem was there before the dyno tune (it was pretty far off on jetting) but I have a hard time believing they didnt notice it on the dyno. It feels almost like a kill switch has been pressed and released for a fraction of a second. Current jetting is at 160 main, 48 pilot, 2nd clip GYTR needle. So here's what Ived tried so far. Battery was loose in the new plastics. Secured it. Checked and cleaned every electrical connection on the quad. Screwed around with my jetting some more. Completely dismantled and cleaned the carb (I did find a bad seal on the slide which I replaced) New Ricky Stator Different CDI Disconnected TORS and TPS Checked valve clearance (its perfect) Nothing has made any difference with the misfire. If anyone has any other ideas before I take this thing into the shop I would appreciate it.