Jet Mikuni Main #175 Hex (4/Pkt)

The Mikuni hex-type main jet in size #175 is a replacement fuel-metering jet for Mikuni carburettors, supplied in a pack of four. The main jet meters fuel through the mid to upper throttle range, so it is the component you change when re-jetting after an intake, exhaust or altitude change, or when freshening a carburettor during a rebuild.

The hexagonal head allows the jet to be fitted and removed with a small spanner or socket rather than a screwdriver, which helps avoid damaging the head on a jet that has been in service for a long time. Buying in a four-pack suits multi-carburettor engines and riders who like to keep spare sizes on the bench while dialling in a tune.

Check your carburettor's specifications before ordering. Mikuni uses several main jet styles, and only carburettors specified for hex-type main jets will accept this part.

• Mikuni main jet in size #175
• Hex-type head for spanner or socket fitment
• Supplied in a pack of four jets
• Meters fuel delivery through the mid to upper throttle range
• Suits Mikuni carburettors specified to use hex-type main jets
• Useful for re-jetting after intake, exhaust or altitude changes, and for carburettor rebuilds

• 4 x Mikuni #175 hex-type main jets

Confirm your carburettor uses hex-type main jets and check the size stamped on the jet body before fitting.
Turn off the fuel tap and drain the float bowl before removing the old jet, and work with the carburettor clean and dry.
Use a correctly fitting small spanner or socket on the hex head rather than pliers, which will round the flats.
Seat the jet gently and stop as soon as it is snug; brass jets are soft and will distort or strip if overtightened.
Never clean a jet with wire, a drill bit or a pin, as this enlarges the orifice and permanently alters fuelling. Soak in carburettor cleaner and blow through with compressed air instead.
Handle jets with clean hands and avoid dropping them, as burrs or damage around the orifice will change how the jet flows.
After re-jetting, check the tune with a plug reading or test rides before making further changes, and re-check jetting whenever you change intake, exhaust or riding altitude.
Fit a clean fuel filter and use fresh fuel to reduce the chance of blockages returning.
Store spare jets in a labelled compartment box so the stamped size stays readable and the jets are not knocked about.