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Main Jet Extension

Part # 122-5000 Be the first to write a review

Main Jet Extension

Main Jet Extension

Estimated Ship Date: 06/26/2026
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5

Emissions

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.

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An improved jet extension design that actually screws into the metering block. The main metering jet then threads into the end of the extension. The installation effectively moves the fuel entry point for the main jet out into the fuel bowl. In this location it cannot be uncovered by fuel, causing a lean condition, during periods of hard acceleration or braking. 2/Pkg.

Features:

  • Improved Design
  • 2 Per Package

About Holley

Holley Performance Brands is the undisputed leader in carburetors, fuel pumps, fuel injection, intake manifolds, fuel injection, and fuel systems.

Brand Holley
CategoryAir and Fuel Delivery
Emission Code5
Extension Inside Diameter0.136 IN
Extension Length0.710 IN
Extension MaterialBrass
Grade TypePerformance
Part TypeCarburetor Metering Jet Extension Kit
Product TypeMain Jet Extension
Sub CategoryCarburetion
WarrantyManufacturer's Limited 90 Day Warranty
UPC090127336779
Part Number122-5000
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.
Requires the use of special "notched" float to achieve proper clearance and to operate properly. Notched float number 116-11 Or Kit with float and extensions 116-10.
Manufacturer's Limited 90 Day Warranty: See Details
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    *Free Shipping and Handling only offered to the contiguous US on orders over $149, excludes clearance parts and oversized packages.

    Some parts are not legal for use in California or other states with similar regulations.