Mikuni 4/042-105 Large Hex Main Jet for Carburetors Jets

The Mikuni 4/042-105 is a precision brass main jet designed for use in most Mikuni carburetors. This large hex-style metering jet controls fuel flow in the carburetor's main circuit, directly affecting engine performance and air-fuel mixture at mid-to-high throttle positions.

Key Features:

• Large hex design for easy installation and removal with standard tools
• Precision-machined brass construction for accurate fuel metering
• Compatible with most Mikuni carburetor models including VM, TM, and HSR series
• Direct replacement OEM Mikuni part number 4/042
• Allows for precise carburetor tuning and jetting adjustments

Main jets are essential tuning components that must be sized correctly for your engine's displacement, modifications, altitude, and operating conditions. The jet size number indicates the fuel flow orifice diameter, with larger numbers flowing more fuel for richer air-fuel mixtures.