make sure that when u open the throttle fully .. the slide inside carb is lifted fully and the venture/bore of carb is fully open ..
try opening the race full and try to feel the slide going up through your finger if seeing is difficult or try to use some sort of mirror .
also make sure that when the carb is fitted it holes are flush with those in the head .. kabi kabar ya holes perfectly match nai hotha .. jis ki waja sa rpm tho barhthi ha but fuel nai andar jatha ..