Mice had chewed the black primer button, so replaced the white plastic end plate that goes on end of black plastic carb body.

Initially didn't include the needle on reassembly - fuel came out of primer button. Tried again with needle (ball end on float, pointy end in outlet?) but would not start.

Fuel comes out of chamber when I remove the white end plate. However, when I test needle in position it doesn't fall up and down easily within tube. Should this have a coil spring somewhere to give a positive movement against the float?

Fuel is good, and everything else worked fine before I dismantled the carb.

BTW, should the end plate have come with a gasket or any other bits? I was charged �8GBP, which seemed a bit steep.

Hope to hear from someone soon - should have mowed the grass before I took the thing apart!!