Bill,

Many thanks for your advice. I must admit that other than at the early running in stages I haven't had the engine running for any length of time on the ground since. I'll be sure to give that a go. I'll also review the way that the fuel tank is mounted before packing it off for any investigative work. Don't think that I'll send it to you though as I live in the UK! Do you know who the distributor is for OS Engines this side of the Pond? Thanks again for your time.

Chocky.