Triumph BSA Norton Wassell Evolution “Premier Type” 30mm L/H and R/H Carburetor Set PN# TBS-09-0450 TBS-0451

Introduced as an economical alternative to the Amal Premier Concentric series of carburetors, the Wassell Evolution range of carburetors feature jets, throttle valves, floats, and needles that are interchangeable with the Amal Concentric series of carburetors. This matching set of left and right-hand 30mm carburetors are direct replacements for the Amal 930 carburetors introduced in late 1967 for the 1968 model year.

The pair of 30mm Evolution carburetors are for intended for use on twin carburetor applications, where 30mm bore manifolds are fitted. Set up for BSA and Triumph 650 and 750 twins, they are supplied with 3.0 throttle valves, .106 needle jets, and 200 main jets. These carburetors can be set up for various applications with changes to the slide cutaways and main jets.

For fitment to Norton 750 Atlas and Commando models, some alterations may be necessary, such as reliefs to the carburetor mounting flanges and inner throttle stop bosses, due to the close proximity of the parallel manifolds on the cylinder head. Other variations in jetting is also likely for this application.

The mounting flanges are fitted to the inlet manifold studs and secured with nuts. The banjo fittings at the bottom of the float bowls are retained with special bolts that allow introduction of fuel into the float bowls. Supplied with choke assemblies. The top cap cable adjusters are removed and the caps are drilled out to accept correct Triumph throttle cables. How to Fit New Concentric Carbs with Old Cables (Triumph) – YouTube

For our 32mm Triumph/BSA ‘Evolution’ carb set for Norton twins CLICK HERE

For the single right hand 30mm ‘Evolution’ carb for TR6 and TR7 models CLICK HERE

For the single left hand 28mm ‘Evolution’ carb for BSA models CLICK HERE