Wouldn't let my hassles put you off trying Brian - the big prob I had was that, despite getting what the book says from Surrey Cycles in the UK - who are really very good, say most people - and a recon one not a replica - I don't know what my AJS might have originally had in terms of jets, needle, slide etc. I stupidly swapped the tired original carb for some bits I needed when I didn't have any money. So its secrets went with it 25 years ago.
I am quite sure a) that my new one will work/would work properly (it's done a few hundred miles at reduced pace already), it's just that I need a selection of jets, needles and maybe even floats if there are choices, to play with, and I don't have any. And b) that a bit more patience than I am prepared to invest would sort it.
The fault's simple, in theory - not enough juice when you want it! But I'm not about to buy in a load of stuff so I can play, particularly if the net result wouldn't be much better than the 376 with its new slide.
One slightly interesting thing is that on this other bike the needle in the Monobloc is not a C (which the 76 takes, per book and per Surrey Cycles) but is unmarked, and a LOT shorter. The engine will only splutter and bang with a C in there, although it will start right enough. It clearly needs to get off the needle a lot quicker than some other engines - which is reflected in the (normal, say other owners) fuel consumption, which is worse (only a 27bhp 500) than the A10. 55ish mpg is about it. Partly also because those engines rev - max 7000, which was a lot for a just-post-war design with 7:1 cr - and need to be allowed to if you want reasonable torque.
As far as the basic quality and fit of my recon 76 goes, it seems fine - all goes together well and no fuel leaks at weak points mentioned in earlier note. But of course, in light of some of what I've just read courtesy of this most excellent forum, I can't say whether the fuel flow through from the float chamber to the body is spot on, or whether there are any other internal faults on any remanufactured parts which may have contributed to my problem. Haven't even looked, to be honest.
Today I simply put the whole thing, covered in WD40 and wax paper, in a box marked 'Amal Type 76, AJS, Main Jet or Other Problem' and stuck it on the shelf next to boxes of other redundant or dead parts which might come in useful. . . my kids will probably find it there when I'm dead! Then I went for a thrash on the thing while the sun was still up. Groily