In 1967, the A50 was outfitted with a single Monobloc 376. While that's a perfectly fine carb, BSA switched to the newer Amal MK.1 Concentric in 1969. Specifically, the 626, which is what I assume came originally on my bike. Of course, here's where it gets funky.
My bike (which I'm finding has had more and more half-assed fixes and weird modifications) came with a crappy chromed-out Amal 928. It's a bigger carb that was used on the A65 Thunderbolt, and it's surprisingly rare, compared to the 930, which can be found everywhere. Upon examination, it's so warped and boogered up that it's getting ditched for a brand new one, which are luckily still being made.
So, you might think, "Hey, just order the 626 like the factory says and be done with it." Fair enough... BUT, the new 928s are being made to awesome new specs, while the 626s are still being made the old fashioned way. Is it a big difference? YES!
The new slides are being made by completely machining them from an all new alloy that prevents the sticking issues with the old style (a big deal). The fuel tickler (this was pre-choke era) is also redesigned so that it doesn't leak gas everywhere, and the body construction is much cleaner than the old versions. All in all, it's a much better build that its' predecessor.
I'm no expert at this stuff, and there's a lot of details that have to be done just right, such as the needle jet, the needle position, the main jet, the pilot, ect. Of course, there's also the option of switching to even newer type of carb, like a Mikuni or a Keihin, and getting features like a choke. My current thought is to get the 928, but have all the jets set to the 626 specs, but I really don't want to set my new engine on fire.
**EDIT** Upon further research and good f*cking timing, I've learned that the 626 carb IS INDEED being made to new premier quality now, and I can get one set up with my factory specs from the retailer. Done deal. So... basically ignore everything I've just said.
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