I just got my giannini motor back with the dellorto carb. I am having a big problem with tunning the carb. There are two screws one for the idle and the other for the air/fuel. I tried many different settings but I can't get the motor to stop bogging. Based on different settings, the motor will either bog at the bottom end or the top. Does anyone have any suggestions on how to tune the carb the right way?