[LizardsA]

Ok everyone, I took messrs Chauvin and Swoft's idea and checked the fuel flow, and voila! I cleaned out the sediment bowl, then when all reassembled, turned on the gas valve under the tank, and there was no flow of fuel, but rather a very slow drip. I have removed and cleaned out the fuel pipe between tank and sediment bowl, which was very dirty, cleaned it out, refitted, and now get a really strong flow. Thanks to all who have lent advice with this problem