1955 DB34 Gold Star

alanbmwgs

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Hi, can anyone please tell me which Carburettor would have been fitted to a 1955 Bd34 Goldie. Would it have been a Monobloc. Many thanks for any replies. :beerjug: :rob
 
I think it would have had an Amal GP carb which are difficult to set up - especially the idling, so most were replaced with monobloc carbs back in the day or, more recently, a Mikuni
 
Thanks Chas, my friend bought the bike off this Forum, it did have a GP carb fitted, but he is having great difficulty starting it. The seller also supplied an Amal Concentric, which he has switched the GP Carb for, on his first ride out with the Concentric on it spluttered to a stop, wouldn’t restart and the plug was sooty black.
I think it would have had an Amal GP carb which are difficult to set up - especially the idling, so most were replaced with monobloc carbs back in the day or, more recently, a Mikuni
 
If your friend wants an easy life (and isn’t planning to race it) then he may benefit from fitting a Mikuni conversion. Amal and other makes of carb can be set up to work but Mikuni is probably the least erratic.
 
The problem with the early Mk1 concentrics is that the floats are no good with modern fuel, and they sink allowing it to flood.
Surrey Cycles does a conversion kit of new float ass'y and a new float needle
 
The problem with the early Mk1 concentrics is that the floats are no good with modern fuel, and they sink allowing it to flood.
Surrey Cycles does a conversion kit of new float ass'y and a new float needle

Amal do a complete refurb kit for modern fuels as well.
 
If the c1955 carb is struggling to cope with modern (E5?) petrol then what about the rest of the fuel / engine components?
Think these can be detuned to make them more everyday reliable eg inc a thin plate under the barrel to reduce compression. To get steady tick over without flooding using a rejetted Amal carb instead of original GP plus touring inlet and scrambler outlet cams.
 
Can you use additives to boost the octane rather than reducing the compression ratio? Making it easier to live with will certainly mean putting the Amal GP in a box for posterity and fitting something more tunable.
 
I think it would have had an Amal GP carb which are difficult to set up - especially the idling, so most were replaced with monobloc carbs back in the day or, more recently, a Mikuni

Yep ... it's my understanding that's what they all came with from the factory

As to tickover/idle? the GP Carb doesn't

Constant blipping when stationary to prevent stalling is the norm :D
 
Yep ... it's my understanding that's what they all came with from the factory

As to tickover/idle? the GP Carb doesn't

Constant blipping when stationary to prevent stalling is the norm :D

The GP carb doesn't have an idle jet ;)

Edward (formally of this parish) has two of the horrible things including an ex works bike.
 


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