If you have problems with your car stumbling or hesitating when you try to give it some throttle, whether off an idle or when driving down the road, then you most likely have an accelerator pump issue going on.
95% of the time, stumbling and/or hesitation issues stem from this on your carburetor... the accelerator pump. Watch the video to see exactly how to solve the problem.
Another common culprit for causing hesitation and stumbling are the squirters. Again, watch the video to see what the problem may be, and exactly how to fix it.