Thanks Ray,
I may be a bit over awed by the AME 0.49, so I will give your suggestion a try and use muffler pressure first! I will leave bladders and crank case pressure until later, assuming I can't get a good run! The engine has the small head and fins, so must be an early version, as you said. So I will watch for the cool running. I have plenty of Merlin plugs and Nelson / Galbreath heads, so I can experiment.
I have heard stories of the AME engines being set up as per book and immediately cutting out on launch. The doomsayers then went on to say that the engine must be run on crank case pressure or bladder (I checked on that!). The culprit was said to be the huge venturi plus the timing of the cylinder. I think that Kenneth's suggestion of decompressing the engine and reducing the venturi diameter will work too. Given the choice I would have preferred the Big Mig 0.49. but just couldn't resist the price ($20 NIB).
Norvel got back to me about the venturi for the 0.61 R/C Big Mig (it is listed under the 0.49 spares and not in the 0.61, so that fooled me). I was drooling over their diesel conversion head too. It had a pretty good write up and 16,100 rpm on an APC 7x3 with the pre Revlite 0.49 AME like mine, is not to be sniffed at. If all else fails then I can go diesel, well I am British, so diesel perfume on your clothes is most desirable!
Thanks everyone,
Andrew.