Did it ever run correctly? If not what have you done? If so when did it change. How is your battery pack voltage. Battery packs can measure correctly and still be junk. 90% of ignition problems can be traced to faultly battery packs. Pull the plug. ground the plug. put on degree wheel, and tell me at the exact degree the spark occurs. It should occur at about 30 degrees before top dead center. You must find top dead center first and adjust your pointer to zero when the pistion is all the way up. Most 2 cycle engines have about 20 degrees of play around top dead center. You must find the middle of that play and call that TDC. Then see where it is firing. Let me know.