1¼” HS2 SU Carbs. 1¼” HS2 SU Carburettors AUD983 (F&R). TRIUMPH SPITFIRE Mk1 & Mk2. Carburettor to Air Filter Gaskets. fit between Carburettor and Air Filter. Top Quality. To date, petrol in the UK has contained up to 5% renewable ethanol (known as E5).