My 80 cc Bikeberry 2 stroke stopped working about a month ago, so i put it up until today. I put a new plug on and a lawn mower plug wire and it ran! I was so a happy. I test rode it for 5 min, parked it, then rode a few miles a while later, went in a store, then wouldnt start when i tried to head home. Has fuel, Petcock is open, no clog in the line (took off carb and gas poured out). I tried disconnecting the kill switch but still nothin. Unscrewed spark plug and pressed against engine while riding. nice fast consistent sparking (except for a few seconds in the middle, but im 75% sure that was me not holding it down while pedaling). Im on my last tank for break in (2 gallons used so far) at 24:1 oil. I know the carb isnt stuck shut or wide open cause i can open it up while pedaling the engine and there's a clear noise difference. Any advice on what else to check?