I had a very frustrating Sunday morning, after the success of Saturaday afternoon getting the tank filler neck to fit flush, I came out on Sunday morning to find that I could hardly move the filler cap. I used a metal wedge to try and rotate it, but only managed about 1.5 turns before it froze. I tried coaxing it with WD40 etc. but nothing worked, so finally I gave up in frustration and screwed it back in as far as it would go. I have ended up with about a 1mm gap at the front and a very slight gap at the back which I guess I can fill with something. I only hope that nothing ever goes wrong with this tank because I am going ot have to cut the nose skin to get it out. Luckily I had finished everything I needed to do as far as fitting it went.