I have a Rocket Gold Star replica (Super Rocket DA10R engine in a B33 frame). The carburettor is as an AMAL 928 concentric. As far as I can see the original carburettor was an AMAL 30mm Monobloc.
Is the 28mm concentric suitable for a Super Rocket (it's very hard to start).
If it should be 30mm is it best to go for a concentric or Monobloc?
The original carb would have been 1 5/32 or 29.4 mm. If the present carb is 28 mm, the worst that will happen is a small reduction in maximum power achievable. In terms of the choice between Concentric and Monobloc, they more or less work in the same way and its just the packaging that is different with the Concentric being the more modern configuration. Unfortunately, many of the problems with starting and running classic bikes can be down to a badly worn carb, especially if it is 50 or more years old!
Quote from: spaceman on 25 Jul, 2022, 08:01 Unfortunately, many of the problems with starting and running classic bikes can be down to a badly worn carb, especially if it is 50 or more years old!
Thanks spaceman. That's what I was worried the problem may be. I'll look for a new carb.
(Just realised I've posted this in 'Singles'. I'm off to count my cylinders :-) )
I WOULD PICK MONOBLOC OVER CONCENTRIC AS THE PILOT JET IS EASY TO ACCESS UNLIKE THE CONCENTRIC