bohay, to determine jet size you have to remove the float bowl. The jets are located in the metering block. They will have a number stamped on them. Also are you rich at idle,mid range, or top end? Check your idle mixture screws on the sides of the metering block. Turn them all the way in then back them out 1 1/4 to 1 1/2 turns to start. Also while you have the bowls off check the power valve make sure it's not blown or does it have a plug? I know it's alot but you need to check it all.