Why would a 49fcc 2 stroke engine bog out at full throttle?

this could be a number of reasons it could be your mixture screw or it could be running lean or rich the best thing to is a plug chop see what colour it is if its black and oily its running rich if its white its runing lean also if its running lean your engine will sound flat and could course it to seize or the main jet could be to big or to small its always best to over jet a a 2stroke and work down till you feel the engine getting better hence the bog going away hope this helps