Related Photo Galleries
While other type of carburetors use metering rods to add additional fuel under moderate to heavy loads, this type of carburetor uses a power valve. Power valves can also be changed to adjust how much and when the additional fuel is added. Power valves used to be susceptible to blow out because of backfire but now a check valve prevents this problem in modern carburetors. Consult manufacturer recommendations when making power valve selections.