My Googling and eBaying has failed me! I am trying to find a petrol tap seal washer for my pit bike carb but have failed miserably.
I can get a complete replacement carb for £8.60 inc shipping from China (see here) but I would rather just replace the seal as the rest of the carb is in perfect condition after de-gumming it.
I have some sheets of the material (from which I make gaskets and seals for the petrol and paraffin camping stoves I collect and restore) and can send you some blanks of it if you fancy making hole punches from appropriately sized tube.