The 2A1 jet needle is only to be used with the 2928/122 .106 needle jet, as it is part of the non-EPA jetting specification as used on the European jetting for Triumph T140E and T140D models.
Applicable to models fitted with Amal MK2 carbs; BSA, Norton and Triumph from 1978.5-1982.
The needle is a tapered rod that interacts with the needle jet to precisely meter fuel at mid-throttle openings. The needle can be adjusted for height by changing the position of the clip. The 2A1 needle features four grooves for clip placement.
The 2A1 jet needle must be used with the 2928/122 .106 needle jet. The position of the needle is adjusted by moving the clip from one groove to another at the top of the needle.
The top cap of the carburetor must be removed to allow access to the slide, which houses the needle. The needle sits in a bore inside of the slide, next to the throttle cable.
Not for use with Amal 600 and 900 series Concentric carburetors.