Mikuni KEIHIN MAIN JET

The Mikuni Keihin main jet is a replacement carburetor metering jet for Keihin-style carburetors. It controls how much fuel flows through the carburetor at mid-to-full throttle. Main jets are also called main fuel jets or carb jets. They are a core part of jetting and tuning on motorcycles, ATVs, and other powersports engines.

Key Features:

• Calibrated metering orifice that sets the fuel flow for the main circuit at high throttle openings
• Replaces a worn, damaged, or varnished jet, or lets you change jetting to suit the engine
• Available in multiple jet sizes, so you can jet richer or leaner for your engine setup, altitude, temperature, and exhaust or intake modifications
• Threads into the main jet holder inside the carburetor float bowl area

Tuning and compatibility notes: Keihin and Mikuni jets use different numbering systems and are not interchangeable between carburetor brands. Choose a jet made for Keihin-style carburetors, and match the jet type to your carburetor. Jet numbers are not directly comparable between brands.

Fitting the correct main jet helps with throttle response, power delivery, and fuel mixture at wide-open throttle. Check that the jet is clean and undamaged before you install it. If you change jet size, check the spark plug reading and engine behavior.