actually the main and pilot jet are under the bowl. However you dont have to take the bowl off to adjust the air fuel screw...there are only 2 screws on the carb that can be adjusted. The one on the left side with the black nob is your idle screw. for the air fuel screw you have to loosen the carb and spin it sideways as far as possible. Now look on the bottom of the carb bowl, you will see a long flange sticking out with a flat head screw in it.....screw it in all the way, then back it out about 2 to 2.5 turns......but its located on the bottom of the bowl inside a long flange.....hope this helps.