Two things happened to me on my 1300. One was the stopcock started to leak by and I forgot to open it. It ran like yours. Dumb moment # 299051 of millions.
Second, my gas cap became "clogged" not allowing air into the tank causing fuel not to flow. Although I did several things, I believe the gasket had become stuck over the vent holes. This tended to happen when I overfilled the tank.
Probably not the solution to your problem, but certainly cheap check.