Jet Mikuni Main #280 Hex (4/Pkt)

The Mikuni Main Jet #280 Hex is a calibrated carburettor jet designed for use with Mikuni carburettors across motorcycles, ATVs, and other powersport applications. Sold in a pack of four, it suits riders undertaking a full carburettor rebuild, re-jetting for a change in altitude or climate, or fine-tuning fuelling after an engine or exhaust modification.

The hex-head format allows clean installation and removal with a standard socket or driver, reducing the risk of damage associated with slotted jets. Having multiple jets on hand makes it practical to trial adjacent sizes during a tuning session or to keep spares ready for future use.

• Pack of 4 jets — practical for tuning across sizes or keeping spares on hand
• #280 jet size for precise main-circuit fuel metering
• Hex-head design for installation and removal with a standard socket — no slot-head damage risk
• OEM-style Mikuni replacement jet for carburettor rebuilds and re-jetting
• Suited to motorcycles, ATVs, and powersport applications running Mikuni carburettors

• 4x Mikuni Main Jet #280 Hex

Use a correctly sized socket or hex driver to install and remove the jet — do not use pliers, which will round the head.
Tighten firmly but do not overtighten; brass jets are easily damaged by excessive torque.
Inspect the jet orifice for blockages or deformation before installation and replace if the orifice is not perfectly round and clean.
To clear a blocked jet, soak in carburettor cleaner then blow through with compressed air — never use wire or drill bits, as this permanently alters the calibrated orifice size.
When re-jetting, adjust and confirm float height and needle clip position before concluding that the main jet alone requires a size change.
Store unused jets in a sealed container away from moisture to prevent oxidation of the brass.