>>28505068
assume you're a retard, did you check for air leaks behind the carb and at the crank seals? is the exhaust tuned to your engine, do you use the right air filter? are your reed valves clean or leaking light?
does it get enough fuel, is the float bowl height set right?
did you mess with the emulsion tube/is it worn out?
id get an air/fuel sensor kit from fleabay for 40ish bucks, weld a bung into the exhaust, and start from there.
always assume you're stupid and you missed something basic like not tightening the spark plug.