if your bulb holds prime and does not lose it after operating motor this eliminates line to fuel pump problem.and you have vent cap open.your carb will have to come off.most of the time you can disassemble clean and reassemble and run perfectly.this runs usually 50 bucks (good ole boy price)to install kit is quite a bit more expensive.your mixture screw sets at-srew all the way in-back out 1 turn-then fine tune while running.