Carb for 88 Dominator

I have an Amal 926 ready for a 1958 88 engine. Not run the engine yet so can't advise on jetting. The new ones are ethanol proof with a stay up float. The Wassell version I noticed were a bit cheaper.

The basic advice is to use the same settings as for the monobloc except the main jet should be 10 - 15% bigger. So for a 240 monobloc main jet, try a 260 or 270 in the concentric. (Isn't that a 626 or am I havering?).

OK this info will probably be all Monobloc, but may assist with reference to Gordon's advice?

http://amalcarb.co.uk/cf/vehicle/list/?manufacturer=Norton&vehicle=Model+88

Good luck

Rgds Steve

Mine came with a single 26mm but I could never get it to perform - it was frankly gutless.

Much better with a28mm.

I'll have to confirm slide but I tried various jets, plug chops etc and ended with a 220. Everyone seems to think that's small so I've been a coward and put a 240 in now. I think it's a bit rich on full bore.

Slide is 3 + 1/2 (but I'd better check when I get home). I played with a number 2 or thereabouts and cut it away until it seemed best. Then bought a chrome plated slide from RGM.

Currently has two 28mm concentrics with identical settings to the one.

I think I have standard (not SS) cam but am not certain.

Regards

David

Rob -it hadthe 26mm version when I bought it. But the head did not have the loose sleeve inserts. Mine is the 'downdraft' head. I have read that it's not good to have a carburettor smaller than the inlet - i.e. it's much better for the airway to get progressively smaller than to get bigger. Maybe with the 26mm it was doing just that - getting bigger after the carb and upsetting gas velocity.

It now does have sleeves, andwith the bigger carb the airway is certainly not stepping back up in size.

I've no recollection of trying the 26mm with sleeves. But as you know - the original was 1+1/16 Monobloc. I'd like a pair of monoblocs as theywere original and it would look better. But I'm not spending well over £300 for littlebenefit.

I thought the three benefits of the concentric were that they are more compact so easier to arrange multiple carbs, and cheaper to make, and less problematic on corners with a vertical bike (i.e. with asidecar). Otherwise they don't give better performance and logically the Monobloc should be better as it has a smooth cylindrical venture. Has anyone done back to backtrials I wonder?

My 88 ran a 1" monobloc very successfully, as indeed does my son's now. I did try a 1 1/16" monobloc at one time and it wasn't any better, possibly rather worse.

My 99 with a downdraught head ran variously twin 28mm carbs, twin 1 1/16" monoblocs and finally a single 1 1/16" monobloc. It was as happy with the single monobloc as with any of the others - even on the racetrack.

Sorry Gordon, 626 it is, I also run one on my Model 50.

Single 928 on my 99 and a 930 on my 650ss.

Hello I like the mono-bloc has the concentric tends to run weak and a good mono- bloc with a number 4 side is just right for this ethanol fuel were getting happy days yours anna j