1972 Roadster Rebuild

dynodave said:
I don't believe the frame is required to do any electrical service at all.
I'd be curious to know if anyone can tell me where, anywhere? what wire or connector or circuit uses the "frame" for electric conduction. IIRC There are 9 grounds in the 71-74 harness all using the red interconnecting wire circuit....
1 headlight bucket (+turn signals), 2WLA, 3engine/head @ headsteady (spark & points current), 4horn, 5battery, 6capacitor, 7rectifier base, 8zener diode stud, 9tail light assy(+turnsignals)
I'll think more on the turn signals but right now I think it is only switched power not grounding controlled.
Click to expand...

You could not be more correct.

Commandos utilise a series wired earthing system, where any component that requires earthing has a wire run to it.

It is quite obvious that many misconstrue that as being "lots of earths", as if somehow the battery has to be randomly connected to the frame for things to work, and that if you repeat that many times, it is better.

As an example, the earth wire that runs to the Zener is to ensure earthing of the Zener, not because that is a good earthing point, but rather it is there because that is definitively not a good earthing point, and the component mounted there needs a good earth.

Interesting aside.
Boyer instructions say to remove the earth wire from the condenser "frame tag" and connect the earth from the Boyer there.
Think about it. What needs to happen is to connect the Boyer to the wire that was on the frame tag.

The MK 3 does use the engine for earth return, once the small earth wires have been disconnected from the battery (as for safety reasons they should be).
 
NorComCycles said:
Interesting aside.
Boyer instructions say to remove the earth wire from the condenser "frame tag" and connect the earth from the Boyer there.
Think about it. What needs to happen is to connect the Boyer to the wire that was on the frame tag.
Click to expand...

That isn't exactly what the instructions say;

http://www.boyerbransden.com/pdf/KIT00053.pdf
13) Remove the red wire from its earthing point on the end of the condensor pack. Reconnect this to the + marked terminal on the left-hand ignition coil.
.

16) Connect the red wire from the transistor box as follows: first connector to the earth tag on the end of the condensor pack, second connector to the + terminal of the left-hand ignition coil with the red wire already connected to it.
Click to expand...

Not only does the Boyer red have a connection to 'frame'/'earth' it also has a connection to the 'return' wiring at the LH coil.
 
L.A.B. said:
That isn't exactly what the instructions say;

http://www.boyerbransden.com/pdf/KIT00053.pdf


Not only does the Boyer red have a connection to 'frame'/'earth' it also has a connection to the 'return' wiring at the LH coil.
Click to expand...

That isn't exactly what the current PDF on their site says, as it has been clearly updated, and I would say quite recently, but that is not important. But what is important is that it is what was stated was until recently, and it was for many years, and it is on the hard copy I have here from before the latest MKIV release(actually from the 80's I think). The point is that even Boyer had it wrong for a long time, in as much as their instructions did not optimise the fitment on a series earth wired machine.

On that latest PDF it now provides for connection to the earth wiring system, which confirms that were "wrong" previously. Otherwise why else would they have changed it?

I have seen (over 35 years mind you, not on a daily basis, I am not saying that) numerous examples of Boyer installations where there was no connection to the earthing system, with the connections only being to the frame, as per the Boyer instructions.
 
NorComCycles said:
That isn't exactly what the current PDF on their site says,
Click to expand...

I think it does! It might not state it directly (why should it?) but if the instructions are followed, the Boyer will have a 'return' connection.


NorComCycles said:
as it has been clearly updated, and I would say quite recently, but that is not important. But what is important is that it is what was stated was until recently, and it was for many years, and it is on the hard copy I have here from before the latest MKIV release(actually from the 80's I think). The point is that even Boyer had it wrong for a long time, in as much as their instructions did not optimise the fitment on a series earth wired machine.

On that latest PDF it now provides for connection to the earth wiring system, which confirms that were "wrong" previously. Otherwise why else would they have changed it?
Click to expand...

I don't think it has been updated all that recently.

An old Micro-MkIII instruction sheet on Brit Cycle says exactly the same at 13 & 16.
http://www.britcycle.com/Manuals/33101inst.pdf

Same instructions at Old Britts for the old MkIII
https://www.oldbritts.com/boyer_install.html
 
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L.A.B. said:
I think it does!
Click to expand...

You mis-understand.

You said "that is not what the instructions say", and I was pointing out "that it is not what the latest updated instructions say", which is completely true(in relation to what the earlier instructions do say).

Understand now?
 
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NorComCycles said:
You mis-understand.

You said "that is not what the instructions say", and I was pointing out "that it is not what the latest updated instructions say", which is completely true(in relation to what the earlier instructions do say).

Understand now?
Click to expand...

o_O
No, you've obviously misunderstood something I've said plus you appear to be entirely wrong about the instructions having been updated "recently".






 
I don't particularly want to become embroiled in the above language bomb tossing.
I will offer that BCS, ol brits copy and their redraw, and the boyer kit00053 are all technically incorrect for the isolatic mounted commando. This is the only situation I will address.
Boyer appears to use a generic drawing version that satisfies an uneducated persons version of the wiring .
Remember one additional irrefutable fact. The red + ground buss wire in the coil area is the + end of the points/coil CAPACITORS. This wire function is to connects to the metal capacitors unified mounting bracket. The mounting bracket can be physically disconnected, retaining the wire, from the frame without any change in the bikes ability to run. That wire is very incorrectly described by boyer, and any one who subscribed to that term, as being a "frame" ground. It's function is the capacitor return through tthe harness.

For the boyer application the wire is repurposed to be the boyer box and coil return. It is NOT now and was not originally functioning as a "frame" electrical connection.
 
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Si tous les dégoûtés s'en vont , il n'y a que les dégoûtants qui restent ..
1972 Roadster Rebuild

Associates degree, Bachelors degree in electronics (1 course short of full double major including mechanical)
20 years US Air Force radar tech, 7 years college level electronics/radar instructor on multimillion dollar systems.
USAF Accomodation Medal during vietnam for saving an already inflight airborn B-52 Arc Light mission, by repairing a failed radar and allowing the mission to not fail. Seems I was the only guy willing and able...to step up to the job that was actually assigned to others including some much higher skill (theoretically on paper) and rank.
15 years at CPI (old Varian) diagnosing and repairing radars for the USN carrier to allow pilots to land(controlled crash).

Oh, I think I do know something about commando wiring too....
 
My bike all have ignition systems... Points/coil, magneto, long dwell and short dwell electronic ignitions. Correct no radars!

While any ignition system on internal combustion engine, yes like any norton, is a childs play electromagnetic pulse generating device of typically 3-7KV requirement. The radars I worked on were a bit upscaled electromagnetic pulse generating device typically from 17 to occasionally 60KV. Peak power, up to, in the many millions of watts.
Since a stock norton horn circuit challenges you, maybe you should not comment on a topic it appears that you have practically zero knowledge in. Obviously you can't tell the difference OR similarity between radar and ignition systems.o_O

If you check out Ludwig's by-line:
Si tous les dégoûtés s'en vont , il n'y a que les dégoûtants qui restent ..
My french is rusty but I "get it" and agree
You would see why the knowledgeable people eventually go away
 
The Purist
by Ogden Nash

I give you now Professor Twist,
A conscientious scientist,
Trustees exclaimed, "He never bungles!"
And sent him off to distant jungles.
Camped on a tropic riverside,
One day he missed his loving bride.
She had, the guide informed him later,
Been eaten by an alligator.
Professor Twist could not but smile.
"You mean," he said, "a crocodile."
 
No, the crocodile has free rein.

A Word to Husbands
by Ogden Nash

To keep your marriage brimming
With love in the loving cup,
Whenever you’re wrong, admit it;
Whenever you’re right, shut up.
 

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