Quick one about me.
Never been a biker or a mechanic, a carpenter by trade. Now retired. Direct access and full A licence last summer.
In 2023 I started looking for my late fathers 1950 B31 to pass on documents to the current keeper. You will see I posted on this forum in 2023 when trying to who had the bike. With help from the BSAOC I did locate the keeper and although it was not my intention to buy the bike, last year the keeper said he was planning on selling it and I got first option to buy it, thus a new A licence followed and I have been riding a Kowasaki Versys for a year.
I picked up the B31 in August last year and I want to use it, not just look at it.
Now the long story.
Its an older May 2004 restoration, and restored very well I believe, I have receipts totalling £1889.59 for parts and images of the bike in bits going through resto. But it has not been used since, just taken to shows in a van, started up, then back in the van to come home and put away until the next show and dry stored.
Externally its in great condition and as the clutch, gearbox and magneto are all new or refurbed it should be good. But after riding it a few times it was obvious I had a few issues. Popping when slowing down, float chamber flooding, lacking power when climbing hills.
I also found the 2004 resto had included a fuel tank re-line, but that has failed with lining material hanging in the tank like curtains. So I now have the tank off and am stripping internally for re-lining.
I also have a couple of really small oil leaks come to light after I had completed a couple of 50 mile trips and everything got warm, maybe gaskets here and there are not good, probably as the bikes has not been ridden since the 2004 resto job.
I removed the carb, ultra sonic cleaned everything, and fitted a service kit. But that made things worse. Carb flooding more and backfire more frequent. So I am thinking the carb may just be worn out as the throttle slide does feel a bit loose.
I am not necessarily going to be taking the bike to classic shows for winning prices, I want a bike that's really reliable. In fact I want a bike where I can tour the UK.
A trip to Ireland from Kent is planned in May. I was going on the 650 kowaski, but hey I would rather do it on the B31 even if it means mainly staying off motorways.
I trust a 2004 restoration but I don't trust the bike is good and reliable.
Therefore, should I put the 276 pre monoblock in a box, send away to be restored, or just upgrade to a newer carb? What other mods if any should I do if I want a bike that needs to be reliable for long trips?
I can do certain maintenance but will be relying on the maintenance sheets and help.
Thanks Steve.
Popping and banging on the overun is usually nothing more than an airleak in the exhaust.
1, where the ex pipe pokes into the head must be airtight
2, where the pipe joins the silencer must be airtight.
Usually these coke up as machine is used , but yours has not had much use.
Remove , reseal and see how it makes an improvement
Quote from: rhyatt on 17 Jan, 2026, 20:18 Popping and banging on the overun is usually nothing more than an airleak in the exhaust.
1, where the ex pipe pokes into the head must be airtight
2, where the pipe joins the silencer must be airtight.
Usually these coke up as machine is used , but yours has not had much use.
Remove , reseal and see how it makes an improvement
Thanks, but I still need to address the carb flooding. I don't need choke to start, just a little tickle and I get fuel, and starts fine. But when I stop turn off and short time later, as soon as fuel switched on the carb just floods all over the place, worrying as the engine is hot. I have to turn off fuel off instantly and start with fuel off, and after it's going for a moment slowly turn fuel on. Indicates stuck float. But I see no reason it should be stuck as all clean.
Have you spoken to Burlen in Salisbury, they make all the Amal parts and sell all the service parts
The float has a needle valve and these don't aways seal when dirt gets in or wear. You can get a rubber tipped valve for about £15 that stops this. Popping and banging is quite common on old bikes, air leaks, lean or rich mix on the over run, ignition timing off. Most people live with it and find the culprit when fixing something else.
B31s are lovely reliable bikes, they do leak a bit but I commuted on one for many years and it never let me down (but lots of tinkering...) . Many years ago I met a guy who had ridden a standard B31 from England to Helsinki and back via France, Holland Germany and Sweden so it will certainly make it to Ireland. Last year I was at an event and there was a guy I a German registered un-restored B31, he'd ridden from Germany and was riding home.
Why not post a travelogue ;D
I am not sure that I can add very much to the sound advice you have received thus far, the exhaust pipe fits into a tube like recess in the head, sometimes it is not a good fit and can be flared slightly but a bit of exhaust sealer around the (cleaned) gap will help, then some more before you slide the cooling ring along the pipe back to the head, but as said with use this will coke up!
The flooding issue can be a number of things from poorly seated float, incorrectly set fuel level, sticking float (bent needle) or, more likely from your description contaminated fuel from delaminating sealer causing the float needle to stick open.
I suggest that you first try starting/running it, after cleaning the float chamber out, with a remote fuel tank (Ebay for £10-15 inc eg https://www.ebay.co.uk/itm/397468148860) and see if that is better, then you know that once your tank is repaired you should be ok. I would also make sure your taps have decent filters (the inlets to the taps can sludge up with silt) or install a couple of in-line filters in each fuel line.
Regarding the carburettor itself there are people that can restore them or you can repair it yourself (new brass sleeve/plastic float kit, new jets and needles will set you back about £120 from someone like Burlens or Hitchcocks which, unless the body is very worn, will fix most things - unlike Mk1 concentrics which wear badly due to metallurgical no-nos!).
Other option is a new 276 https://accessories.hitchcocksmotorcycles.com/Amal-Carburettors/276-Pre-Monobloc/12539 £400+ ( ouch! but quick, simple and reliable) a new Monoblock https://accessories.hitchcocksmotorcycles.com/30020 £250+ or a Concentric https://accessories.hitchcocksmotorcycles.com/Amal-Carburettors/600-Mk1-Concentric-4-Stroke/13616 probably need to spec the Premier variety on a concentric https://amalcarb.co.uk/mk-i-concentric-series/600-series/base-line-specifications/24mm-bore/aluminium-premier-lh-24mm-4-stroke-carburettor.html as the premier has the modified pilot system, suitably coated slide, stay up float and viton tipped lightweight alloy float needle.
Always ask for it to be supplied to the correct spec (the seller should set this up for you for your bike).
I'm sure that I don't need to tell you that for a longish trip like you are planning I would tape or tiewrap a prelubed spare clutch cable, front brake cable and throttle cable and couple of litres of oil (same will do for engine/gearbox and clutch) and a spare inner tube and a simple tool roll to be able to replace the above.
A B31 will not set the world on fire but will take you anywhere and back once running properly.
Quote from: rhyatt on 17 Jan, 2026, 21:35 Have you spoken to Burlen in Salisbury, they make all the Amal parts and sell all the service parts
I was on their website last night. I'll need to call them. I could see the component parts listed for my pre monoblock but not a full replacement. I'm sure it's there, just couldn't see it. I'm thinking of going concentric type as may be more reliable.
Quote from: rhyatt on 17 Jan, 2026, 21:35 Have you spoken to Burlen in Salisbury, they make all the Amal parts and sell all the service parts
Not spoken to them yet, but I will. I was on their website last night to see whats available. Thanks.
Hi,
No amount of new parts can restore a worn out carb. The small fuel and air passages wear over time and even if clean will skew any settings. You may get your bike running OK but if you want to use it regularly and for longer trips then a new carb. is probably the best option.
Many riders have fitted an Amal Concentric to a B31 so there will be plenty of ideas re jetting but as already mentioned, ask Hitchcocks for the best jetting options.
Unless you really enjoy fettling, a new carb. properly set up is a fit and (almost) forget item.
For the exhaust pipe sealing I use a high temp. silicon sealant. Works well and is easily pulled out when needed.
Dave.
If it is flooding when the tap is turned on, that means your float is not closing the valve correctly.
It should be an easy fix. First make sure the float is floating and is not filled with petrol.
Then by using a length of new hose, check the action of the valve by raising the float, whilst blowing into the tube. The float should have some travel remaining when the air stops going through the valve.
If you have the carb off the engine, the air should stop just with the weight of the float, when the carb is held upside down.
As it is a pre monobloc carb, with the separate float bowl. Is the float bowl vertical when the leaks occur? You might have it leaning on the side stand, or worse, it could have a wrongly installed 'tilted' float bowl.... They are available with 0 10 30 or more degrees of tilt, to suite different installations.
Quote from: DAVE BRADY on 18 Jan, 2026, 11:27 Hi,
No amount of new parts can restore a worn out carb. The small fuel and air passages wear over time and even if clean will skew any settings. You may get your bike running OK but if you want to use it regularly and for longer trips then a new carb. is probably the best option.
Many riders have fitted an Amal Concentric to a B31 so there will be plenty of ideas re jetting but as already mentioned, ask Hitchcocks for the best jetting options.
Unless you really enjoy fettling, a new carb. properly set up is a fit and (almost) forget item.
For the exhaust pipe sealing I use a high temp. silicon sealant. Works well and is easily pulled out when needed.
Dave.
Thanks Dave. I am of the mindset its a new carb, I just needed the push.
I was planing on touring on the Kowasaki, but I only started riding in the first place because I was ably to get my Dads old bike. And if I don't use it properly, it will just sit in a shed, one day the roof will leak un-noticed and will get rusty etc etc. So I want it to be my go to bike.
All the best. Steve
if you are getting the tank re lined make sure the material used to line in is ethanol resistant .mine came off after years of working one the new fuels arrived .
why not use an Amal 376/2 Monobloc carb . I had one on my gold star for a while and it ran perfect . Started good and ticked over good . I wanted the gp carb on mine which is now running good with it but takes a lot of work . If i were going touring i would refit the monobloc 376 .
Quote from: the chippy on 18 Jan, 2026, 10:32 Quote from: rhyatt on 17 Jan, 2026, 21:35 Have you spoken to Burlen in Salisbury, they make all the Amal parts and sell all the service parts
I was on their website last night. I'll need to call them. I could see the component parts listed for my pre monoblock but not a full replacement. I'm sure it's there, just couldn't see it. I'm thinking of going concentric type as may be more reliable.
I have a Monobloc on my 1948 B32 it works perfectly, no issues at all. The Monobloc is a more robust carb than the Concentric and is preferred by many riders. It also has a replaceable pilot jet whereas the Concentic is fixed with a "one size fits all". And it's cheaper.
By chance, you don't have a fibre washer UNDER the banjo union where it screws into the float chamber ?
Burlens are very helpful lot.
They bought all the Amal factory tooling and records etc.
Things to carry with you ---
As you use the bike and it settles and evolves , you will generate your own list of tools and bits to carry.
Personally , pliers , pertinent screwdrivers , a few relevant spanners , chain adjusting spanners taped together , spare chain link , magneto spanners.
Are you 12v or original 6v ? If you're 6v then a few light bulbs or consider changing to 12v and led bulbs and easier life for the dynamo .
I'm going to join in the "why not fit a ...." discussion, but my suggestion is for an Amal Premier. The 276 you have currently are known to be problematic with shutting off the fuel supply, hence the usual advice of shutting off the petrol tap as soon as you stop.
The Premier gives a tickover like a metronome, and usefully the pilot jet is removable without a carb strip. Keep that 276 and pass it on to the next owner when you come to sell.
Fit a decent fuel line filter and don't rely on the filters in the fuel taps and carb inlet; the in-line filters are much finer.
You might consider a mag overhaul as they degrade whether in use or not. A simple Easi-Cap will probably suffice.
Quote from: ducati2242 on 18 Jan, 2026, 12:44 why not use an Amal 376/2 Monobloc carb . I had one on my gold star for a while and it ran perfect . Started good and ticked over good . I wanted the gp carb on mine which is now running good with it but takes a lot of work . If i were going touring i would refit the monobloc 376 .
I shall make enquiries regarding a carb replacement and keep the original tucked away. Thanks
Quote from: V500 on 18 Jan, 2026, 17:45 I'm going to join in the "why not fit a ...." discussion, but my suggestion is for an Amal Premier. The 276 you have currently are known to be problematic with shutting off the fuel supply, hence the usual advice of shutting off the petrol tap as soon as you stop.
The Premier gives a tickover like a metronome, and usefully the pilot jet is removable without a carb strip. Keep that 276 and pass it on to the next owner when you come to sell.
Fit a decent fuel line filter and don't rely on the filters in the fuel taps and carb inlet; the in-line filters are much finer.
You might consider a mag overhaul as they degrade whether in use or not. A simple Easi-Cap will probably suffice.
I believe this is what I shall do, and keep the original pre mono tucked away. I have looked at the receipts and I see £395 was paid in 2004 for the mag to re refurbished. £120 labour the rest parts and VAT. but I get your point. There is a company near me, Sussex magnetos, I will call them to discuss it. Thanks.
Quote from: rhyatt on 18 Jan, 2026, 13:52 By chance, you don't have a fibre washer UNDER the banjo union where it screws into the float chamber ?
Burlens are very helpful lot.
They bought all the Amal factory tooling and records etc.
Things to carry with you ---
As you use the bike and it settles and evolves , you will generate your own list of tools and bits to carry.
Personally , pliers , pertinent screwdrivers , a few relevant spanners , chain adjusting spanners taped together , spare chain link , magneto spanners.
Are you 12v or original 6v ? If you're 6v then a few light bulbs or consider changing to 12v and led bulbs and easier life for the dynamo .
Thanks for this. I believe all the washers on the carb are correct, but I may just upgrade the carb anyway. I would love to do a 12v conversion and something I am looking at. thanks Steve.
Quote from: ducati2242 on 18 Jan, 2026, 12:36 if you are getting the tank re lined make sure the material used to line in is ethanol resistant .mine came off after years of working one the new fuels arrived .
Will do thanks for the advice. Steve.
Quote from: scifi on 18 Jan, 2026, 12:04 If it is flooding when the tap is turned on, that means your float is not closing the valve correctly.
It should be an easy fix. First make sure the float is floating and is not filled with petrol.
Then by using a length of new hose, check the action of the valve by raising the float, whilst blowing into the tube. The float should have some travel remaining when the air stops going through the valve.
If you have the carb off the engine, the air should stop just with the weight of the float, when the carb is held upside down.
As it is a pre monobloc carb, with the separate float bowl. Is the float bowl vertical when the leaks occur? You might have it leaning on the side stand, or worse, it could have a wrongly installed 'tilted' float bowl.... They are available with 0 10 30 or more degrees of tilt, to suite different installations.
I am looking at replacing the carb now, but I shall tinker first with what you say about the hose and blowing. The float is fine as in floats well. And I do not think anything is installed incorrectly, and the bike is not leaning its on centre stand. I will have a play. Thank you, Steve.
Don't rush to do the 12v conversion. I have one bike on 12v and one on 6v and there's really no difference. Converting to 12v used to be "a thing" mostly because you got a better headlamp. But now the LED bulbs in 6v are so good this advantage has gone. Once you go all LED the load on the dynamo comes down and you get good charging even with the lights on. A 6v set up will start charging from lower revs which can be quite helpful and the 6v battery has large cells. I have found going to a DVR2 solid state regulator has been worth it, it charges cleanly at lower revs and seems better at exciting the dynamo than the mechanical reg. I changed to neg earth, because there was a better choice of LED bulbs, but now there are very good ones that are not polarity sensitive and are sensibly priced.
DVR2 is an excellent unit, the similarly-named VReg2...avoid like the plague.
I'll second that, I got a Vreg2 and it went into the bin after a week. DVR2 worked out the box and its still working.
Quote from: limeyrob on 19 Jan, 2026, 07:52 Don't rush to do the 12v conversion. I have one bike on 12v and one on 6v and there's really no difference. Converting to 12v used to be "a thing" mostly because you got a better headlamp. But now the LED bulbs in 6v are so good this advantage has gone. Once you go all LED the load on the dynamo comes down and you get good charging even with the lights on. A 6v set up will start charging from lower revs which can be quite helpful and the 6v battery has large cells. I have found going to a DVR2 solid state regulator has been worth it, it charges cleanly at lower revs and seems better at exciting the dynamo than the mechanical reg. I changed to neg earth, because there was a better choice of LED bulbs, but now there are very good ones that are not polarity sensitive and are sensibly priced.
Hi,
As I want to try some long tours this year I wanted to run some 12V tech, 12v usb socket, and some sort of discreet loop recording camera. I'm not liking riding without dash cam. Even if I revert to gopro type I'm limited on battery life whereas loop is just forget it.
All original parts will be kept so anything I do will be reversible.
I have already fitted 6v led headlight bulb and if I dont do 12v will look into led tail/stop light options.
And now I have to investigate what a DVR2 is, lol. And I like the idea of converting to neg earth for the convenience of LEDs.
All the best and thanks. Steve
I recently fitted an LED stop/tail. Its very good BUT, the pins on the bulb are a bit small. I had to put blobs of solder on them to get it to stay in the holder.
USB is 5v so you should be able to run a USB port off 6v, check the fine print.
If the bike is charging happily on 6v and its original mechanical regulator and everything working happily electrically , then frankly I'd leave well alone .
I run my bikes on 6v and have no issues.
Only if your charging starts to "wobble" then consider the electronic regulator.
The USB output is 5v for your phones and GPS etc , but they all have 12v input.
Explore 6v cars to discover using usb, there must be classic 6v vw beetles and porsche 356 driving about with usb and sat navs plugged in
failing that - find a handlebar usb socket from ebay https://www.ebay.co.uk/itm/187216269667
and lash it up to a 6 volt battery to see what happens - nothing to lose really
I got a CPT USB power supply off e-bay for the Land Rover, 5 years and a lot of damp and vibration its still working fine. It says 12V input with 5v out but on the spec its listed as 8v to 22v input so at under £5 you could experiment. These thing come with 2 USB sockets on tails so you can hide the box and poke the leads out, I bought 2 because I was sure it wouldn't last, the spare is sill in its box. The sockets are plated steel and get corroded but at £5 you have cut them some slack.
Going 12volt has the advantage of less voltage drop in the system. Also the easier availability of components.
Quote from: limeyrob on 20 Jan, 2026, 07:29 I recently fitted an LED stop/tail. Its very good BUT, the pins on the bulb are a bit small. I had to put blobs of solder on them to get it to stay in the holder.
USB is 5v so you should be able to run a USB port off 6v, check the fine print.
You reminded me, I have to do a better job of my led headlight bulb, I thought it ok, as fine in the workshop after fitting but first time on the road the bulb connection was loose. And good point on usb. Thanks.
Quote from: idie on 20 Jan, 2026, 11:07 Going 12volt has the advantage of less voltage drop in the system. Also the easier availability of components.
Yes I watched a good youtube video how the 12v battery has better for power usage as it needs less amps. Not quite got my head around it but I am working on it.
Thanks Steve.
Quote from: rhyatt on 20 Jan, 2026, 08:18 If the bike is charging happily on 6v and its original mechanical regulator and everything working happily electrically , then frankly I'd leave well alone .
I run my bikes on 6v and have no issues.
Only if your charging starts to "wobble" then consider the electronic regulator.
The USB output is 5v for your phones and GPS etc , but they all have 12v input.
Explore 6v cars to discover using usb, there must be classic 6v vw beetles and porsche 356 driving about with usb and sat navs plugged in
failing that - find a handlebar usb socket from ebay https://www.ebay.co.uk/itm/187216269667
and lash it up to a 6 volt battery to see what happens - nothing to lose really
Thank you for that advise. I can now see that to some extent connecting to a 6v supply is not really an issue. I think it will be trial. Thanks Steve.
Quote from: limeyrob on 20 Jan, 2026, 10:24 I got a CPT USB power supply off e-bay for the Land Rover, 5 years and a lot of damp and vibration its still working fine. It says 12V input with 5v out but on the spec its listed as 8v to 22v input so at under £5 you could experiment. These thing come with 2 USB sockets on tails so you can hide the box and poke the leads out, I bought 2 because I was sure it wouldn't last, the spare is sill in its box. The sockets are plated steel and get corroded but at £5 you have cut them some slack.
Thank you, this has got me thinking now. I have some experimenting to do. All the best Steve.
I've just read through this thread - a lot of content in a few days. Fascinating and hats off to you for wanting to ride, not show, your B31. I've only ridden one B31, once, a mid 50s springer and they are just so usable and a real pleasure - that one even stopped reasonably well.
In all the posts (and I'm aware the discussion has moved from the original fuel topic onto electrics) I haven't seen any mention of E5 vs E10 fuel. As a matter of course I only use E5 (except in emergencies) and never store it in the bike when laid up, draining both the tank and the fuel system as the ethanol makes it hygroscopic. I even add Putoline E10 fuel fighter to the stored fuel for good measure. There will be plenty of discussions elsewhere about the merits and demerits of different fuels but, on the whole, modern fuels can really mess with the way old bikes run (especially those in a higher state of tune, so clearly not a B31) and if recommended carbs settings don't seem to improve running you may have to alter ignition timing, etc. or even those carb settings, but I'd go with the recommended settings first then look at ignition timing.
Andy
I too have gone all E5. In the past I used to run old bikes, especially those with manual ign timing, on the cheapest petrol I could get. Many were designed to run on pool petrol which was very low octane. But I've had a lot of problems with E10 on older vehicles, the bio-ethanol is an aggressive solvent and absorbs a lot of water.
Quote from: createscript on 21 Jan, 2026, 08:23 I've just read through this thread - a lot of content in a few days. Fascinating and hats off to you for wanting to ride, not show, your B31. I've only ridden one B31, once, a mid 50s springer and they are just so usable and a real pleasure - that one even stopped reasonably well.
In all the posts (and I'm aware the discussion has moved from the original fuel topic onto electrics) I haven't seen any mention of E5 vs E10 fuel. As a matter of course I only use E5 (except in emergencies) and never store it in the bike when laid up, draining both the tank and the fuel system as the ethanol makes it hygroscopic. I even add Putoline E10 fuel fighter to the stored fuel for good measure. There will be plenty of discussions elsewhere about the merits and demerits of different fuels but, on the whole, modern fuels can really mess with the way old bikes run (especially those in a higher state of tune, so clearly not a B31) and if recommended carbs settings don't seem to improve running you may have to alter ignition timing, etc. or even those carb settings, but I'd go with the recommended settings first then look at ignition timing.
Andy
Hi Andy. My biggest issue is a lack of knowledge regarding biking in general. In fact until 2023 I hated motorbikes, noisy, dangerous things, so my Dad said as he never wanted me to have a bike, His Brother in Law had a terrible crash which paralyzed his pillion. Anyway I just happened to be clearing my loft, sorting though old photos, saw the 1950s ones of Mum and Dad on EDY (its reg is EDY 96) looked on DVLA and saw it was registered still. And all I felt I wanted to do then was contact the keeper and pass on copies of the photos and other documents for EDY. And then I got the bike and I just love riding them. Wish I had started decades ago. So sitting on a motorcycle for the first time age 68 means its been a steep learning curve. I am 70 now and last year after passing my bike test it was learning how to ride and starting my advanced training. My Dad sold this bike in 1956 when I was 1 year old so he wasn't a biker long, needed the money to buy his first car. But between 1950 and 56 he rode it a lot. In fact he got the bike so he could get back to South London from Catterick Yorkshire to see his girlfriend, my Mum. when he had a weekend of leave from his obligatory National Service in the Royal Signals. Then when he was working as a plumbers mate would ride from job to job with a plumbers tool bag on his back.
So one of the trips I would like to do this summer is recreate a trip up to Catterick. The other is see my Granddaughter in Ireland.
At the moment the important thing is to know the bike will be reliable. Get some miles under my belt so I can, how shall I say it? mould myself to the bike, become one with it.
I also want to do the work on it myself, again so if and when I have issues, hopefully I can resolve them, or at least diagnose them.
And yes, for my comfort and safety I would like some tech, navigation and camera. I am used to riding my Kowasaki 650 so have all of that and music in my ears, lol.
I had issues with the Ewerts fuel tap, that took a lot of removing, stripping, cork replacing and refitting to stop it leaking petrol. So now I'm on the tank relining issues, tank strip came today.
Still not 100% decided what to do with the carb, I am of a mind to fit a mono block.
My head is a real muddle about the 6 or 12v scenario. Ignoring the classic bike enthusiast view of keeping it original, I do understand that, there are very good reasons to go 12v. If as I originally thought, I would keep the bike as a museum piece the pre mono would stay, the 6v will stay, etc etc. But the problem is I REALLY want to ride it a lot. So although I don't want to change the look of the bike or do anything none reversible, I feel I need to do a bit so I am not calling out recovery, I can see and be seen at night and for it to be practical.
I would add, I have great fun on my 650 Versys but it's a completely different type of fun on the B31.
Thanks Steve.
Quote from: limeyrob on 21 Jan, 2026, 11:14 I too have gone all E5. In the past I used to run old bikes, especially those with manual ign timing, on the cheapest petrol I could get. Many were designed to run on pool petrol which was very low octane. But I've had a lot of problems with E10 on older vehicles, the bio-ethanol is an aggressive solvent and absorbs a lot of water.
The guy I bought the bike from used E5. He never filled the tank as he only used the bike a couple of times a year to show at classic bike shows, but he did have several other classics and recommended E5 and said he never had issues.
Steve.
Good for you in your search.
My son is recently recreating bike adventures that I made in the late 60 s.
Your desire for mechanical empathy is very important when riding these older machines and this empathy and deep "feel" for the bikes ensures confidence when out and about.
I understand equally the dilemma about 6 and 12v , but why not leave well alone and concentrate on the bits that aren't working and prioritise those.
You need the carb sorted to get it running and enable you to get out and about and settle into the machine.
You'll enjoy both the learning /fiddling journey and eventual ride certainly
Lovely story! Don't worry about the 6v vs 12v. Its an easy change over at any time.
Don't forget we want a travelogue!
I agree, don't worry about the 6v vs 12v. The modern LED bulb replacements available for nearly all the old bulbs mean that the current draw is minimal (some might say too small) for excellent output and 6v circuits nowadays need not prevent you riding in the dark or gloomy conditions as long as the dynamo, voltage regulation and all the wires and connections are sound. Just make sure that the LED bulbs are either polarity agnostic or you get the right ones for your wiring setup (likely +ve earth)
On the other hand, before getting too far into the dreaming and planning of big trips, why not get the bike going reliably (possibly keeping the old carb and staying at 6V) and trying some longer more local trips?
You won't be the first to suddenly realise that the "romanticism of old bikes" isn't really for you at all, moreso as you're a late starter into the old bike world?
One breakdown on a dark road and in the rain could end the dream forever...
In the broader context of upgrading parts for reliability, there's this curious thing that old British bikes don't really like being dismantled nor being left standing. I've seen so many old bikes that are, frankly, ratty old heaps but have been like that for nearly 50 years, gradually and progressively deteriorating on their wheels, and yet in regular use and just keep running and running, maybe sub-optimally but they don't leave their owners completely stranded.
Conversely, where I've bought an old bike and 'fixed' just about everything that's apparently broken or worn out, confident that it'll serve me well as a result, it has often done just the opposite.
Call it something a bit mystical if you will, or just call me superstitious (which I'm not really) but I'm not the only one holding this view.
I'd say, fix any obvious red flag items (poor wiring and connections, cracked tyres, bad leakages etc.), carry out the necessary maintenance tasks, feed it good fluids where needed, but more than anything, keep using it - if it doesn't let you down in 10 x 20 mile excursions, it'll probably manage 200 mile days just as well, but if it does let you down, you'll at least be close to home.
I hold a similar view, and not just with experiences of old bikes. Tried and tested machinery and plant can suddenly become unreliable if someone starts fannying-around with various aspects and components.
In common slang, "You've let the good fairy out".
Quote from: V500 on 23 Jan, 2026, 10:29 On the other hand, before getting too far into the dreaming and planning of big trips, why not get the bike going reliably (possibly keeping the old carb and staying at 6V) and trying some longer more local trips?
You won't be the first to suddenly realise that the "romanticism of old bikes" isn't really for you at all, moreso as you're a late starter into the old bike world?
One breakdown on a dark road and in the rain could end the dream forever...
If you have a good magneto you most likely won't break down on a wet night. You don't need lecky for a magneto. I have had my B33 50 years now.The most reliable bike I've had.
I had my B31 for about 20 years and commuted over 30 miles every day for 3 years and it never broke down. It took a bit of servicing but always worked.
My B33 has done me proud for 50 years. If you have a good magneto you know you don't need electrics to keep going.
We can all recount stories of X number of years riding reliable old bikes, and we can also all no doubt recount stories of breakdowns at the worst times too.
Plenty of reasons why a bike stops running, and it's far from just mag problems.