Needles

The needle profile is the primary mixture-control component in an SU carburettor. Its taper determines fuel delivery at every throttle position — fitting the wrong needle is the most common cause of persistent rich or weak running that no amount of jet height adjustment can correct.

SU Specialists stocks over 100 genuine OEM needle profiles covering every standard application. Needles are identified by a two or three letter code stamped on the shank — always verify this before ordering. HS-series carburettors use a straight-shanked needle retained by a grub screw. HIF-series carburettors use a biased needle with an off-centre clip — not interchangeable with HS needles.

Use our needle recommendations guide to find the correct rich, standard and weak needle for your vehicle. Our identification guide explains how to read your needle code.