Holley 125-55 Carburetor Power Valve

There still seems to be a lot of misconception about Holley carburetors blowing power valves. Nothing could be further from the truth. Holley performance carburetors built since 1992 have utilized a power valve check system that effectively eliminated this infrequent problem. Consisting of a spring, brass seat and check ball, the check ball system is 100 percent effective protecting the power valve diaphragm from damage due to engine backfire.The power valve check ball is designed to be normally open but quickly seals to close off the internal vacuum passage when a backfire occurs. Once closed, the check valve interrupts the pressure wave generated by the backfire, thus protecting the power valve diaphragm. There is no way that the power valves diaphragm can rupture due to an engine backfire!

• Single-Stage Power Valve; Standard Flow; 5.5 in. Hg.;
• Single-Stage Power Valve
• Holley Performance Emission Code 5: This part is legal for sale or use on Emissions Controlled Vehicles; Uncontrolled (Non-Emissions Controlled) Vehicles; and Racing Use Only Vehicles because it does not affect vehicle emissions and is not covered by emissions regulations
• Includes Gasket
• Single-Stage Power Valve Standard Flow 5.5 in. Hg
• Power Valves
• Opening Vacuum 5.5 in. Hg