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If, "correctly wired" then the ignition switch connects to coil(+).
http://www.boyerbransden.com/pdf/KIT00052.pdf

Hi Nick,
"ground" doesn't have anything to with "measur[ing] volts".

Volts are simply the units of difference between two points in an electrical circuit - e.g. between a battery's negative and positive terminals.

By-and-large, you cannot measure Volts in any circuit containing a B-B e.i. or one of the clones, because they all incorporate the 'feature' pioneered by Bransden - having powered-up the e.i. and coil(s) by turning on the ignition switch, if the Box doesn't 'detect engine movement' (signals from the Stator being generated by the Rotor turning), the Box powers-down.

If it happens, this power-down is a varying number of seconds after power-up. If it happens, the ignition circuit is not complete; any circuit nor complete, any "measur[ing] volts" is pointless, tells you the proverbial ten per cent of bugger all.

You have not understood all the VB article ...

By-and-large, a battery is the power in any Direct Current electrical circuit. There is no such thing as a "negative ground" battery or a "positive ground" battery, they all work exactly the same. The current must always pass through an e.i. (any electronics) in the same direction.

Proper DC regulation, high-output 3-phase alternator doesn't damage a 7 Ah burglar alarm battery ...



Two more things with e.i., particularly B-B and clones:-

. I advise against connecting it to "FRAME EARTH" - "negative ground", connect Box White wire directly to battery -ve, through a low-Amps fuse (start with 5A, depending on the coil(s), you might need 7.5A).

. There should be a specific Black (assuming standard Lucas wire colours) wire between battery -ve and an engine component - head bolt(?). You should not rely on the engine's connection to the frame nor random wire connections to frame components.

Hth.

Regards,

And when do most BSA's end up with proper DC regulation ?
Most require a load from the battery to smooth out the pulsed voltage
Also a lot of gel cells have a maximum rate of discharge & recharge otherwise the electrolyte breaks down or gasses.
And the cheaper the battery the lower the surface area of the plates so the fewer amps needed to cause damage.

Stuart, where specifically do you attach a wire to the (BSA) engine? Obviously not head BOLT, since those are inside the rocker chamber, perhaps head STUD, although a wire there would require a second nut on the stud, it would be ugly, and it would be subject to heat. On an OIF model, you could use one of the head steady bolts in the rocker cover, but a dry frame model does not have those. I use the front end of the head steady, but my head steady is chromed; if the head steady is painted, it would require removing the paint at the mount points. Perhaps you meant one of the rocker cover studs or bolts? Anyway, not a big deal, but I'm curious because the subject has come up many times.

Hi Mark,
Firstly, apologies, the end of the sentence was not punctuated correctly. I have corrected it in my original post, it now reads, "There should be a specific Black ... wire between battery -ve and an engine component - head bolt(?)"; i.e. head bolt is a suggestion for Nick H The O.P., who is working with a Triumph engine, with exposed head bolts.

On a BSA (or any engine without exposed head bolts), the important parts of the sentences are, "There should be a specific ... wire between battery ... and an engine component ... You should not rely on the engine's connection to the frame nor random wire connections to frame components."

Nevertheless, as this is more generalised advice than specifically for Nick H The O.P.:-

. Standard Britbike harness, the wire might already be present.

. The intention of the existing/advised wire is the engine has good electrical contact with whichever is the battery 'ground' terminal. As you know, electrical components screwed on to the engine tend to 'ground' through their mounting on the engine, an electrical circuit isn't complete without good contact with both battery terminals; regrettably, the electrical path from engine to battery is frequently neglected.

Hth.

Regards,

red wire , center rear , rocker cover stud
http://www.rcycle.com/Lightning_135__1024x768_.JPG
for a more discreet look
it could be done as a bare copper wire , ( its a ground wire and does not need insulation )

Hi Trevor,
The sentence you've quoted was my agreement with part of one of Nick H The O.P.'s posts:-
As for your rhetorical question, educated guess says you're dissatisfied with the regulation by the standard Zeners fitted to BSA's with 12V electrics? If so, fit a modern reg./rec.?

Hth.

Regards,

Well this is all very educational which is why I'm here after all. I don't mind being wrong and don't care to defend what I do.

However

Quinten and Stuart are telling me I can't measure voltage at the coil in my negative "ground" (I've learned to always put it in quotes) installation
or I've done something wrong. . This is the VB article I was using.

http://vintagebikemagazine.com/technical-articles/Boyer-trouble-shooting/

(Unfortunately the author switched the battery labelling on two diagrams which confused me for a bit)

I made a jumper from the black wire coil to "ground" and measured at the red wire coil. It measured battery voltage less any loss from the switch, etc.

Even without the jumper I still measure battery voltage at the coil.

You both have a lot more electrical knowledge than I do
So what am I doing wrong?

not sure whats hooked up and not hooked up
when you get your voltage readings and where youre putting the meter probes .

With the jumper in place for neg. ground ... jumper between black wire and coil ... jumper to gound
... ignition on ...the voltage reading should be zero at the jumper .
you can trace the voltage drop around the circuit as it meets resistance .
the voltage before the first coil may be lower than voltage across battery terminals ... indicating wire and switch loss .
and the voltage will be half remaining voltage between the coils
and zero voltage after the second coil .

and battery circuit voltage will be somewhat lower than resting voltage , indicating the coil load ... but still above 10volts
... 10 volts being the safe low voltage at which the B-box will still latch and time correctly without Jitter .

the battery voltage under coil load is also testing the battery strength .
a bigger drop indicates of a weaker battery ... and or a smaller battery with less reserve .
..........
dont know if your negitive wiring is correct ?
look at fig 3 and fig 4 below
the wiring for the Boyer is the same for pos. and neg . ground ... only the switch location moves ( the fuse moves to ,
if you follow the convention of fusing the switch slde )

https://triumphbonneville120.co.uk/resources/Boyer%2000052%20Electronic%20Ignition%203.jpg.opt888x1256o0%2C0s888x1256.jpg

That's ok Stuart, I understand the principle; I just know you have BSAs and I was looking for a suggested wire location. Trevor replied with "rear center rocker cover stud", which is a good subtle location. The front end of the head steady works for me since my head steady is chromed, and my "ground wire" from the headlamp shell is also attached there.

Hi Nick,
Uh-uh; to clarify:-
. on your bike, "negative ground" means metal bits of the bike are connected to battery -ve;

. "black wire coil" means the (B-B) Transistor Box Black wire is connected to coil -ve;

. "I made a jumper from the black wire coil to "ground"" means you connected battery -ve to coil -ve; i.e. you bypassed the Transistor Box, it was not in the circuit that you were measuring Volts, your Volts readings were (should've been) accurate.

However, afaict this is incorrect ...

. First you measure between battery -ve and battery +ve, to get a reference = none of the bike's electrical components involved;

. then you can measure between:-

.. coil -ve ("black wire coil") and battery +ve;

.. battery -ve and coil +ve ("red wire coil");

.. note the opposition of the two terminals in each phrase, because the coil/s is/are the resistance in the ignition circuit;

.. if there isn't any additional resistance in any other component in the ignition circuit (e.g. across fuse, ignition switch, kill switch, etc), the Volts readings above between each coil terminal and battery terminal should be the same as the first reading just between the battery terminals;

. so there should not be "any loss from the switch, etc."; if there is, the component/s where this "loss" occurs is/are faulty.

This measurement only while the B-B Transistor Box is conducting; when it switches off, any Volts readings anywhere in the ignition circuit are same as they would be if the ignition or kill switches were off, any fuse was out or blown, etc.

'Fraid I have no idea what this means ...

As I posted earlier, and you can see in the B-B wiring diagrams, any e.i. is connected exactly the same, totally and utterly irrelevant of "ground". In the case of B-B or Pazon/Wassell clones, the Box White wire is connected to battery -ve, the box Red wire is connected to battery +ve, the Box Black wire is connected to coil -ve (only one coil -ve in the case of multiple coils), (one) coil +ve is connected to battery +ve. That's the ignition circuit. The position of any switches within the circuit might be different but they are (should be) simply connections within the circuit.

Because any e.i. is connected exactly the same, irrelevant of "ground", if the e.i. Box is powered down, the ignition circuit is not complete, any Volts 'readings' aren't meaningful. Bugger-all to do with "ground", "negative" or 'positive'.

Hth.

Regards,

Hi Quinten; why is safe to use a bare ground wire? Is that is just grounded? I am confused by the idea that if a battery has 2 poles the current would go from one passing for the wiring and finishing on the other pole? Or is not that way?
Decades ago I saw that in houses but as I am not interested in Electricity theory etc I forgot about it.

Thanks

Having a bare ground wire is as safe as having bare sections of frame or engine.

a low voltage DC earth side doesn't need insulation to function correctly .
the insulation on the gound side only add a layer of protection against accidents .
you " could " wire the ground side harness in all bare copper wire .
(theres probably a trailer Queen Chopper somewhere build this way )

many parts of a motorcycle ground-side are not insulated .
some are conductive paths , some are just bonded to ground to convey a known polarity .
the engine is part of the ground path , its not -insulated .
the handlebars are un insulated and even if rubber mounted
are likely conductive through the clutch cable .
the frame is bonded to ground . paint insulates the frame
but any of the nuts and bolts attached to the frame may be un-insulated earth points .

adding a few inches of bare copper bond between engine and earth harness
adds little to the mass of already non -insulated engine .

do live wires fall off and contact engines , handlebars or aluminum fenders ?
yes , I suppose they do sometimes , but most of the time the lack of insulation isn't an issue .

nowdays , and for some time ,
Conductive metal bits are all bonded to the ground side with copper bond straps
even if the bits are not intended to be the pimary conductive ground path .
and this includes all bare metal conductive bits .

back when cars had chrome bumpers you could jump a dead battery in one car
by kissing 2 car bumpers together to form a negative connection , Through both frames
and then add only one jumper wire from battery+ to battery +.

except if it were the fairly common 6 volt positive ground vehicles... but then you could jump the negative car to the positive car ,use the cables for a series connection and a 12 volt boost for starting..

Here is my insulated jumper from my small battery to the engine mount on my dreaded Choppa.

So, not sure why my Boyer wasn't sparking initially whether the plugs weren't well "grounded" or the Boyer hadn't turned on yet
but it's working now so I don't hate it but there is something about a points ignition transparency of operation that is attractive.

you might want to look at what is chafing your chain, those polished plates don't look too promising

and whilst your down there, fit a cover plate between the chain and the battery. It might be in a box, but theres a lot of grease and sh** that will by flying about down there.

Hi,
How is the B-B Transistor Box supplied?

Almost certainly "the plugs weren't well "grounded"". Always a problem when checking any ignition, even points - plug out of the engine and laid on it, if it doesn't spark, is it just its electrical connection or another problem? Long-term problem like you've just experienced, always worth eliminating this basic possibility by wrapping bare wire around the plug and connecting it directly to the battery 'ground' terminal.

Turning on the ignition switch, the Box should also be on, the Box'll only turn off if you spend too long chatting, fiddling with things you should've fiddled with before you turned on the ignition switch, etc. Nevertheless, no question the Box powering-down 'feature' is a rrpita when trouble-shooting, far too much 'loss' for the illusory 'gain' of allegedly 'saving' the battery.

Nothing obscure about an e.i., at least not any for these old heaps. Like troubleshooting anything, you just need to know how it should work then figure out which bit isn't.

On a vehicle, it's only safe to use a bare ground wire if you can guarantee it will never touch something that is 'not ground'. Because when it does, that's a short.

Also uninsulated ground wire corrodes.

So why wouldn't you just use an insulated ground wire and give yourself one less thing to worry about?

Hth.

Regards,

The ground wire in house wiring is a safety feature. Under normal conditions it carries no current, unlike the "ground" cable on automotive circuits which is in fact a return to the battery, not a ground.

Where would I even find an uninsulated wire?

I once had trouble finding a fault on a Honda 250 G5. Everything worked except the electric starter, which just clicked.

Turned out the large battery return cable had corroded into powder inside its insulation. The ends looked fine!

This is a problem. Most wires (I’m also including oxygen free speaker cable here and speaking of wires in general and not specific to a task) will let air and moisture past the insulation. Which then can’t escape, then oxidation and corrosion sets in.

Hi Stuart; I do not want to use a bare wire just trying to understand the concept behind.

Hi DavidP; that is where my confusion resides. The returning; or as you say on the other hand: "the ground"

Hi TT,
There's earthing braid - thin strands to be flexible, lots of 'em to be able to carry a large current, strands braided to avoid having to cover 'em in something to keep 'em together.

However, no covering, the stuff corrodes. Original Lucas rear lamps used on US versions '66-'70 and then everything '71/'72, the 'frame' inside to mount lens and bulb holder was in two pieces, Lucas wrapped an itsy-bitsy teen-weeny bit of braid between the two bits of the frame. 'Course, fifty-plus years on, its corroded to nothing, leaving people wondering how the bulb's supposed to 'earth'/'ground'.

I had something similar on a Kwak trailie in the 1980's - the main Red wire to battery +ve wasn't conducting so I cut it back to fit a new terminal ... stripped the insulation but bits of conductor came with it, stripped another bit of insulation, more bits of conductor ... turned out all the strands had corroded randomly into short lengths about an inch long within the insulation ... But weirdly, just that wire, all the others on the bike were fine ...

Regards,

Getting this thread back on track, I'm getting a spark with the Boyer and 93% sure I have it wired correctly but the bike is not starting.

Compression not great but should be enough. Carbs are chromed Monoblocs that I've not tried before. I tried slight advance and retard but no luck.
Plugs are getting wet with gas.

This is starting to feel like a couple years ago when I gave up and went to points on my other Triumph.

So it's points again on this one. Zip tie a 12V dual Emgo coil to the frame and break out points and condensers.

First kick. Bang she's running.
(See thread title)

S'pose I'll be sending this MKIV to be tested again.

Are you using this Emgo coil with the Boyer also?