It is a fuel injection model. I can't see any petcock. Interestingly, I thought of doing another test. It was all working fine and firing up in my garage all morning. Took it out to the garden & put it under the sun for an hour or so. Now it won't start, it is not particularly a warm day but it is sunny here in Berkshire (the tank got warm under the sun). The fuel pump doesn't make any noise whatsoever when the ignition is ON! Nothing! I have not moved it back in the garage yet, so I could investigate a bit further. I have just disconnected the battery to see that will reset the Fuel Pump by any chance (long shut but I thought worth a try).