Installed new rebuilt carbs. Took them down to the bodies. Replaced shaft seals, air/fuel adjustment screw o-rings, fuel distribution pipe o-rings, float valves, and float bowl gaskets. Also replaced Carb 1 and 2 diaphragms. Rubber/fabric damaged beyond repair. Bench synched. Wet set float levels. Synchronized carbs and color tuned. Took bike out and ran like a cheetah with it's tail on fire. Held idle well. Pulled the plugs and they were white. While bike was hot did a propane check on input boots, shaft seals, etc. Nothing changed the rpm. Went back with color tune plug and richened up to where a saw orange on all 4 cylinders. Resyched and took bike back out for ride. Still ran well. Pulled plugs and all four are still white. I am pretty sure float levels are set correct. Could this be alignment issues with butterfly valves seeping air through? If that was the case wouldn't the idle be messed up? Any suggestions on what to check next would be appreciated.