I put my RED STICKERED (yes, California) 08 YZ450F away in June when it was approximately 70-80 degrees and it was running well. I pulled it out this week and started her with the old gas ... some popping as though it's very lean. Figured it was the old gas so I went on with getting her race ready - checked valves, replaced oil/coolant/lubed bearings/etc and cleaned her up. Started her again and the same irritating pop on decel. The gas I used this time was old but it was in a metal race gas container so I figure it's still good. I cranked the fuel screw open about 3.5 turns and it gets better but still pops a bit. This usually tells me to go up on the pilot but I'm already at 48 and it was running fine prior to storage (btw, running 160 main, stock everything else at about 1800 ft in Santa Cruz Mtns ---- about 95 degrees today). What gives? Carb needs cleaning? Air leak somewhere?