Guess what, yes, I've had it firing.
Simple really, only spark, petrol and compression to consider!
A trick I read somewhere, could have been on this forum, put a teaspoonful of petrol into the plug hole. Terriffic, fired virtually instantly! but only for a few seconds, of course.
So now we know where the trouble lies. When I bought it the petcock (petrol tap) was blocked solid and the carb was bad as well. I though I'd cleaned them but it look as though there is still some blockage somewhere. I think probably a new petcock wouldn;t go amiss. Any advice on removing it. It doesn't want to come out. I can see that there is a thin tube going inside the tank, presumably the reserve pipe but there also seems to be a plastic washer or tube which stops me from pulling the petcock right out of the tank. Can I force this plastic tube out? I think this will release the head of the reserve pipe.
Great news though?