Classic Motorcycle Fuel / Petrol Pull-On Tap Plunger & Cork. BSA, AJS, Norton Classic Motorcycle Fuel / Petrol Pull-On Tap Plunger & Cork. Knob marked: Pull On. Overall plunger length 26mm. As fitted to a wide range of British classic motorcycles like: AJS, Ariel, BSA, Sunbeam, Silk, Scott, Triumph, Royal Enfield, Norton, Matchless, Velocette etc.