I have just stripped down my carburettor on my 1961 GF. It has obviously had a hard life like the rest of the bike. I have taken some photos and it is obvious that I need a new new slide £45 and repair kit £50. I would still have an old carb with some new bits. Also it needs cleaning and I assume the best way is to have it ultrasonically cleaned and I am nor sure of the cost.
A new carburettor is £207. At £110 difference I should have less trouble than my old one. I have read that carburettors do wear out. I have never seen this bike run so I do not know how the carburettor works.
My questions are
1. when do I give on my old carburettor?
2. If I get a new one is the 389/45 still the best one to get?
3. If I stick with the existing one what parts should I be buying?
John
Hi,
In my opinion and what I have done:
1. Give up now and buy new, it saves money in the long run
2. Give Amal a call and use their expertise.
3. Repair kit, throttle valve, stay up float, choke kit, springs and needle seating kit. I guess resleeve it and replace all the internals , unfortunately no guarantee.
Best wishes...
Hi,
That carb is knackered.
No amount of cleaning will compensate for the wear in the tiny fuel/air ways. Buy a new one and use the BSA spec. You will not regret it.
Dave.
Well I see a trend here so I have decided to invest and buy one. But can any help which one I buy?
I have a 1961 BSA A10 golden flash. The engine is rebuilt to standard Golden Flash specifications (compression ratio, cams etc) and I plan to use one of Amal conical air filters.
On the Amal Vehicle Search there are two options
A10 Golden Flash
A10 Golden Flash Twin
The first specifies a 376/214 for 1969 onwards
The second specifies 389/45 for 1960 to 1961
Haynes suggest 376
BSA Spares diagrams list 389/45
So which one?
John
Hi,
A few years back I made a carburetor spreadsheet across the A7/A10 range. I have 379/45 for your engine, although I suggest giving Amal a call they will advise.
Best wishes...
The 1960 on Golden Flash was specified as 389/45, which is 1 1/8 inch bore.
The 376 was used up to 1959 season then the inlet in the head was opened slightly from 1 1/16 to 1 1/8 inch for 1960 and it got a bigger bore carb. (the 376 body only went to 1 1/16 inch bore, the 389 series had a bigger body and took from 1 1/8 bore up to 1 3/16)
The original 389/45 had a plain intake which did not have a thread on the end that plain end was to retain a rubber conection to the air filter body. So you could not screw a bell mouth or filter onto it. The original carbs were stamped with the specification on the mounting flange.
Below from the 1955-61 Amal settings list.
If in doubt phone and speak to the supplier Amal or Hitchcocks or Surrey Cycle being some.
Hi,
Sorry , fat fingers, as Julian says 389/45 not 379/45.
Bets wishes...
Many thanks to you all. Once again I am in awe of the knowledge available through this forum.
The carburettor is stamped 376/81. I have measured the inlet bore of the cylinder head and it is 1 1/8" bore.
I know I cannot trust anything on this bike and feel lucky that the cylinder head is is the correct one for a 1961 A10. I would not have been surprised if it had been an earlier one or even off an A7.
Another good reason for buying a new carburettor. I can now order a 389 with confidence. Although I will talk to them first.
John