At this point I am grasping for anything trying to figure out my carb tuning maladies, even ready to call the local tribal chief for a ceremonial dance! Seriously, some of you have been very helpful over the past month providing valuable input, but I cant get the midrange and top dialed in. At this point the only thing that comes to mind is this: What does the adjusting screw on the throttle valve assembly do? Is it connected to the TPS? First time when had the carb opened, I removed the screw and removed the slide. When I put it back together, it all went well – no binding etc. But, I did not pay attention to any adjustment. With the carburetor in hand and looking at the end that connects to the cylinder, the throttle valve is not completely closed (about 1/8 gap) that can see the daylight through. Should the valve completely close? If yes, then can this be part of the problem not being able to get jetting right? Does messing around with the throttle valve adjusting screw affect TPS adjustment? Current setup info: Main jet: 172 (Have tried 165-175) Pilot: 45 (have tried 48) Fuel Screw: 1 1/2 turns out (no effect what so ever as to what setting) Needle: OBDVR raised to 5th clip position (tried 3rd, 4th, 5th) Grey wire cut Octopus removed, holes plugged MAJ #100 YZ timed Clean air filter Air box lid removed Stock exhaust with vortip insert Problem: Regardless what jetting combo I am using: Bike starts first kick Idles perfect Midrange sucks (burbling or popping sounds) Top end sucks (burbling sound) Also, at midrange, the bike sounds like it is whistling --- more like air scaping through a hole. is this an air leak???