Some vintage mowers have the old push-off/pull-on fuel taps. These taps have round cork seal rings on the central carrier. Over time the cork loses resilience and shrinks which causes the tap to leak. New or replacement seals are hard to find, so here’s a way to rejuvenate them without dismantling the tap completely. Try cooking the seal lightly with a gas torch. Don’t set it on fire, and remember that the seal will be impregnated with fuel, so it needs to be thoroughly washed and dried first. Also, for the same reason do this well away from the fuel tank.