When I were young (1963) I worked in a Motorcycle shop which had petrol and oil sales. One customer came in on an Ariel Leader (250cc 2 stroke twin) with all the bits, in fact he dressed in a suit! He refused all attempts to serve him two stroke from the plunger, we had a special Castrol mixing funnel in to which you poured the Castrol XL oil and then the correct amount of petrol. He was the only one to use that funnel and his bike had a clean exhaust!
