I'm having a strange issue that has now consumed 3 weekend days of headaches to get nowhere but worse and back. I'm getting some small backfires and popping while revving. The issue started the last time riding when I noticed the bike would stall if it was hot and I blipped the throttle off idle coming out of a turn or any situation snapping the throttle quickly off idle. Slowly revving hot or cold it has popping when trying to hold a higher RPM with the trottle, and certainly will backfire when snapping the throttle if it doesn't stall first. Now its parked in the garage while I try and get things right before riding again. For those "jetting is your issue here" people, please let me know where I'm going wrong then. Here's what I've tried the past couple weeks: Current jetting; Main 165, Pilot 75, Needle 4th clip. Tried 2-6 needle clip positions with no noticeable change. New CR8E plug Borrowed another working coil, CDI unit, and even the harness from the CDI. Original coil metered out fine anyway. Unplugged the neutral wire, and unplugged the throttle position sensor. pulled out the carb and cleaned it twice. all jets in great shape. changed the o-rings and whatnot in the carb. Accelerator pump shouldn't have much to do with this but I did try and advance it a little. Valves all checked and dead center of "in-spec" checked resistance of the stator coils and pickup magneto, all center of the "in-spec" range Visually inspected the coils and all look good to me. bolts are tight. Timing is good finally, new fuel. 93 with ethanol treatment which has always worked for me. Anybody have any insight to this? I cant seem to get any good direction from searching here or google. Thanks!