These Speedmaster carburetors are equipped with all-new Tru-Set needle and seats, which have eliminated the need for external adjustments. This change allows for easier 'bolt-on-and-go' performance. The floats have been factory-set for optimum fuel levels at 3 to 6 psi of fuel pressure and should never need adjustment. If you're running over 6 psi of fuel pressure, a fuel regulator is required. These carburetors also include a new, refined appearance on their float bowls, main bodies, and vacuum secondary caps. Along with having upgraded choke caps for smoother engine warm-up and better cold drivability, these carbs are also the perfect upgrades for any ride.