Author Topic: Looking for some carb advice please.  (Read 385 times)

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Offline ianinglis

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Re: Looking for some carb advice please.
« Reply #30 on: January 10, 2019, 08:27:57 pm »
it doesnt. i was speaking from experience - and you cant buy that!



ian
BSA C10L 1956 - JFO 588
BSA C10L 1954 - MVE 107
RM6 RALEIGH RUNABOUT
ENFIELD DIESEL KUBOTA OC 95
BSA M21 RIGID RKN 816
CBF 1000
BSA ARIEL 3

Online hampshirebiker

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Re: Looking for some carb advice please.
« Reply #31 on: January 10, 2019, 08:30:52 pm »
I don't think it has anything to do with the positioning of the float alone, it's a completely different design. I do know that the airways that are cast in to the body of the concentric are a sod to clear in comparison to the separate jet block in the Monobloc.
Postal - Liphook Hants - But just into West Sussex.

Offline ianinglis

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Re: Looking for some carb advice please.
« Reply #32 on: January 10, 2019, 08:34:25 pm »
and you can get a monoblock the correct size whereas the 622 concentric is slightly too big



ian
BSA C10L 1956 - JFO 588
BSA C10L 1954 - MVE 107
RM6 RALEIGH RUNABOUT
ENFIELD DIESEL KUBOTA OC 95
BSA M21 RIGID RKN 816
CBF 1000
BSA ARIEL 3

Offline timsdad

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Re: Looking for some carb advice please.
« Reply #33 on: January 11, 2019, 07:15:22 am »
My experience is different to yours, Ian. My 1966 Triumph still has, I think, its original Amal Concentric carb and this week the mileage has just gone over the 85,000 mark so it's oil change time. It had done about 34,000 miles when I bought it and the thing starts first kick every time, hot or cold, unless it's my fault. It fires up on a cold morning and will immediately just stand and tick over on its prop stand. It runs clean as a whistle, crank and bores are still standard size and I haven't touched the screws in the carb for about twenty thousand miles. I cleaned the float chamber out about last October or November when I had a mis-fire but that was down to a bare coil wire rubbing on the underside of the tank.

Folk often complain about Amal Mk 1 Concentrics but, like old BSA oil pumps and various Lucas parts, I just fix any minor problems and have no complaints. I've had several new bikes over the years, Brit, Italian and Jap, so I know what old bikes are up against. It helps that I use my bikes regularly.

The Amal Comcentrics were much cheaper to make because, as Ian noted, of their less complicated design and that was progress at the time. I like the Monoblocs too, they're no trouble either, but they cost much more to buy and are no improvement on my bikes. Any slight difference in choke size is negligible on a C11, in my opinion,  - it's not a Goldie.

You pays your money and you makes your choice!


Ray
Just a motorcyclist.

Offline grsymes

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Re: Looking for some carb advice please.
« Reply #34 on: January 11, 2019, 06:05:16 pm »
I have a rebuilt carb     that I might let it go.  I live in Canada

I sent you a PM, did you get it?
1949 Rigid Frame ZC10 5687
1950 Engine ZC11 11149
Slowly coming together

Offline stev60

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Re: Looking for some carb advice please.
« Reply #35 on: January 11, 2019, 07:36:41 pm »
Yes, I see no problem with Amals, in general. I did buy a new pair of Concs some years back and the buggers were still full of swarf from the machining processes, but the Amal Premier I bought back in the Autumn for the A7 means it now ticks over like the proverbial Swiss watch. Very impressed.
When I've bought used Amals (like 276s) in the past I've only worried about the model and choke size, and disregarded the suffixes as there's a possibility that the jets etc will need playing around with anyway.
I agree with the amal concentric premier for the A7, its like its made for the bike, always starts with a gentle kick, idles perfectly, and even with a small main jet, really flys

Offline stev60

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Re: Looking for some carb advice please.
« Reply #36 on: January 11, 2019, 08:02:43 pm »
Im running concentrics on C10 and C11 with no problems, just the time spent getting needle position and jet size right, ive found running a larger main than the original carb had seems to work better, and having a spacer between carb and manifold as well. I had the same situation with machining crap in a new carb, I believe amal are getting there carbs made somewhere in Asia. Ive got my eye on a C10 in parts if its at the right price, I will go for it, and use a monobloc this time   

Offline timsdad

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Re: Looking for some carb advice please.
« Reply #37 on: January 12, 2019, 08:23:51 am »
I think the needle position and bigger main jet is down to the different fuel we have these days, Steve, compared to what was available when BSA set their specifications. Also, the carb' spacer is also often needed now to prevent the increased heat-transfer from modern fuel. These minor differences are not unique to BSA but the folk who're just tinkering with a C11 as their return to motorcycling may not realise this.

I know the Wassell carbs, that are replicas of the Amal Concentrics, are made in Asia and had quality problems in their early days but I thought the genuine Amals, that have always been available from Burlen since Amal disappeared, were made in the UK. Things change, though!


Ray
Just a motorcyclist.