I mistakenly adjusted the "Pumper adjustment screw" on my 2000 426 Keihin FCR carb. The screw is located under the cable pulley on the right side of the carb and adjusts the amount of gas that is squirted everytime you twist the throttle. Yamaha recomends that you don't mess with the stock setting (MY MISTAKE). I can't find any reference in the Shop Manual on how to adjust this. Please, any suggestions?