This unique kit is designed to allow one to adjust the main jet metering of a carburetor without having to remove the fuel bowl(s) to access the main jets. The carburetor can now be calibrated on the motor saving time and avoiding fuel spills.
This is accomplished simply by turning the metering needle that is part of the Adjust-A-Jet metering plate. The metering plate is installed between the carburetor's fuel bowl and original metering block. The needle is completely adjustable and metering changes are easily accomplished once the embossed calibration markings on the needle are noted and referenced. Each of these markings designate 1/8th of a turn. By referring to a handy metering correlation chart included as part of the kit, you can accurately richen or lean the carburetor's main metering calibration. The carburetor can be tuned even when the engine is running.
Adjust-A-Jet can be used on any kind of vehicle. It does not affect the carburetor in any other way, so everything that you've ever learned about a Holley carburetor still applies. Adjust-A-Jet, CNC machined from 6061 T-6 aluminum, can even be used with a power valve plug installed in the carburetor's metering block. Does not fit Holley HP carbs.