Hello
I am contemplating some improvements.
Replacing the old leaky carb (276), I thought about a concentric and wonder about size and jets etc?
It is currently 6v, which is not really an issue, but wondered about an LED bulbs
Also a modern regulator?
Does anyone have any experience or advice about these?
Thank you
Matthew
I have a 1949 B31 that had a worn out 276 and fitted a Mikcarb VM25 as used on the basic Indian 350 Royal Enfield £45 off Ebay. It was intended only as an interim measure but works so well out of the box I have no intention of changing it.
DVR2 electronic regulator likewise works well with a gel battery.
My 1948 B32 (same engine as B31) has a 376/2 Monobloc. Starts easily and runs perfectly. I'm also running it at 12V with V2-Reg 2A voltage regulator and LED bulbs throughout. When I bought the bike the dynamo needed rebuilt so I fitted it with 12V field coil and armature. This isn't necessary to get 12V out of a 6V dynamo but otherwise it will struggle to maintain a charge at in town speeds if the lights are on. If your bike is +ve earth make sure that any LEDs you fit are designed for that as they are usually polarity sensitive.
Morning Mathew
The type 276 carburettor is noted for being a leaky instrument but providing the slide and body are not worn they can be made less leaky and may be worth doing. It's mainly the fibre washers that leak between the float chamber and main body if these are in good condition it might be worthwhile getting the kit from amal carburettors and rebuilding your carburettor. With care in reassembly they can be OK.
LED lights definitely the way to go but they are quite expensive.
And a modern regulator is a massive improvement.
Hope that's of help
Use a Wipac Quadoptic headlamp and led Bulb like a Night Eye 25 watt equal to 70 watt output
I have these on all my bikes.
If you do change to 12v you may be advised to change the old 6v wireing also. Wireing suddenly burning out can be a problem
Quote from: tdc on 05 Jan, 2025, 22:50 If you do change to 12v you may be advised to change the old 6v wireing also. Wireing suddenly burning out can be a problem
The wires are no different 6V or 12V, in fact 6V needs heavier wires because the currents tend to be higher but any loom which is in such a poor condition should be replaced irrespective of the operating voltage.
Quote from: Derek996 on 06 Jan, 2025, 11:36 Quote from: tdc on 05 Jan, 2025, 22:50 If you do change to 12v you may be advised to change the old 6v wireing also. Wireing suddenly burning out can be a problem
The wires are no different 6V or 12V, in fact 6V needs heavier wires because the currents tend to be higher but any loom which is in such a poor condition should be replaced irrespective of the operating voltage.
Well fance that !
Good old Ohm's Law. 6 volts feeding a 24 watt bulb takes 4 amps; 12 volts for the same bulb 2 amps. Not allowing for heating effects etc.
I always use thinwall 1mm square cable which is available in all the Lucas colours and is rated up to 16.5 amps. Like this:
https://www.almsolutions.co.uk/index.php?main_page=product_info&cPath=3_60&products_id=42
froom my local supplier.
Also available on mail order from Vintage Wiring Supplies. Good website too, and they sell it by the metre.
i have bought an led pilot and headlight bulb off the internet and now run with the herd at night time.
better to be seen and no more charging issue with juicy, aftermarket electronic ignition.
Thank you for all the advice.
I might try and service the 276.
I wondered how I densify the slide, it is marked 6/4 on top side is this 1 1/2?
What slide should it have?
Thank you
Matthew
According to the BSA parts lists. Your bike should have a 276DR/1 AT carburettor, I have no idea what the letters mean. It has a 150 main jet, slide is a 6/4, needle in position 3 and a .1065 needle jet. I hope that helps.
A daft question which I should know the answer to - is the needle position counted from the top or bottom? My bikes have always had it in 3 ie the middle one but my Electra is position 4......
Quote from: iansoady on 07 Jan, 2025, 11:45 A daft question which I should know the answer to - is the needle position counted from the top or bottom? My bikes have always had it in 3 ie the middle one but my Electra is position 4......
I've often wondered that too, although I think it's logical to count from the top (leanest position) to the bottom (richest position).
That's what I thought but would be nice to get confirmation. I'll ask Amal.
According to Amal from their FAQs
"Needle Clip position, top down or bottom up?
Something that crops up all the time is whether you count the needle clip slot from the top down or bottom up. With all Amal carburettors the clip position is top down."
Many thanks Derek, I did try to contact Amal via their website but no reply. I should have checked the FAQs!