389 1 1/8" Monobloc Carb
The monobloc carb was introduced in 1955 to solve the problems associated with separate floats. It was widely used on Triumph, BSA, Norton, and countless other bikes until the introduction of the concentric in 1967.
The 389 series is the largest of the monobloc range. Amal is producing these new carbs on new tooling and the results are outstanding. These carbs are set up with a #3 slide, 300 main jet, #20 pilot jet, and a 106 needle jet. The bore size is 1 1/8" or 28.575mm. Amal part number 389/3632. Equipped with the new StayUp float, it is also guaranteed for two years.