Does you carb have the black cap in the square box of picture #1. If so, under that cap is an idle jet that needs cleaning. Suggestion, go purchase Techumseh kit #631021B and build the carb. You will also need a #5 crochet hook to remove the float needle seat. The old wire which holds the float needle to the float can be used ti clean the small idle jet. You need to work it in and out of the end until you see it in the side holes. Good luck.