SU Fixed Metering Needle — Code BB4 | BB4 | SU Specialists

Genuine SU fixed metering needle, code BB4, for SU carburettors with a .090in jet.

• Needle code: BB4
• Type: Fixed
• Jet size: .090in
• Profile stations: 13

Needle profile

Diameter in inches at each station, measured every 1/8in down the needle from the shoulder (station 1). A smaller diameter gives a richer mixture at that point. Stations 1–2 set the idle, 3–6 cover part throttle, cruising and pickup, and 7–9 the top end and full throttle on a 1¼in carburettor.

Not sure which needle you need? Use Find My Kit or send us your carburettor details and we will check it for you.