The bike has smoke coming out of the exhaust at idle I can get up to 30 mph but then it just bogs out and it back firing here and there. I have a 70cc cylinder, high comp head, tecno bullet pipe. I had the 19mm PHBG carb on ther with a 21mm intake and thought I was just hopeless for tuning it. So I put the stock 14.12 carb and intake back on and it's doing the same thing. Its killing my I can't ride this thing.