Flat Spot

Has any one ever delt with a flat spot in there carb? I can be cruisin down the road and get alittle heavy on the peddle and shell fall fat on her face I tried to different carbs and get the same results I think its a lean condition but it didnt do it with the old cam in it ill kick it around to see what you guys come up with

A stock hei dist accel super coil on top dist accel wires autolte 23 no advance kit stock advance springs 16 initial 34 total

never had a proble before i installed new cam and reassembled the motor

ILL go get the trade talk and see who i can find thanks ill let you know what happens