Older Amal 930"s

jms · 2026-09-04T15:33:02-0600

So several years ago when I started to restore my Dunstall Atlas it came with Amal Concentric 930 carbs. They are not Premiers. I really have no idea how old they were but decided to give them a try. The bodies looked ok as did the slides. Fast forward to build completion the bike starts easily every time but when I sync the cards with my Carbmate I can get the motor to idle down around 1000 rpm but the idle is erratic. Now I'm no expert on Amals and have a lot more experience tuning Dellorto's and Bings but I'm guessing it's because they are worn. I wouldn't think that new slides in a worn bore would be money well spent either. Man those Premiers are expensive!

Matchless · 2026-09-04T16:08:53-0600

Reassuringly expensive I would suggest. The Premiers are excellent & worth every penny. I've fitted several sets now, & if Amal had made them this well in the first place Brit bikes would have run better for longer. In the end I guess they just made what BSA/Triumph & Norton Villiers would pay for.

hybridracer · 2026-09-04T16:46:27-0600

jms said:
So several years ago when I started to restore my Dunstall Atlas it came with Amal Concentric 930 carbs. They are not Premiers. I really have no idea how old they were but decided to give them a try. The bodies looked ok as did the slides. Fast forward to build completion the bike starts easily every time but when I sync the cards with my Carbmate I can get the motor to idle down around 1000 rpm but the idle is erratic. Now I'm no expert on Amals and have a lot more experience tuning Dellorto's and Bings but I'm guessing it's because they are worn. I wouldn't think that new slides in a worn bore would be money well spent either. Man those Premiers are expensive!

You've got a Dunstall Atlas, why are you worrying about an erratic idle?

jms · 2026-09-04T16:49:52-0600

Documented! Good point

Older Amal 930"s

jms

Matchless

hybridracer

jms

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