Both of my 3 screws su carbs were rebuilt by ztherapy in November 2014 as per the sheet attached. However, i have noticed that if i dial both fuel mixture knobs to 3 turns clockwise, the front carb spark plugs still turn out leaner than the rear carb spark plugs. Could there be a mistake on the sm needles diameter provided by ztherapy? Could they have mistakenly installed different needles on one carb and on the other and the adjustment is not paired.