What am I looking at?

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@gtiller.
Updated information for my "custom wiring diagram" :) :) :)
Directionals has been completely removed on the bike. The R/R is the A REG ONE.
Powerbox was briefly installed but removed since I had the same problem with Power box as with the A REG ONE
I strongly believe the problem is in the wiring. ( Ref earlier post)
 
@Kjell happy to help - hopefully it will make life easier when troubleshooting.

Did you want the turn signals pulled out of the wiring diagram, or do you plan to reinstate them?
 
@Kjell happy to help - hopefully it will make life easier when troubleshooting.

Did you want the turn signals pulled out of the wiring diagram, or do you plan to reinstate them?
Pulled out of the wiring diagram entirely.

They will never be installed. And since there will no other owners of this bike than me (at least until I am 6 feet under)
simplifying things is important
 
@gtiller.
Another thing I came to think of. Somebody on this forum correctly observed that my bike was not a 1972 model but a 1971 (engine number 20M3S15xxx. It was registered originally as a 1972 in the US

It is my understanding that the 71 had a 3 way ignition switch and not the 4 way ?
 
@gtiller.
Another thing I came to think of. Somebody on this forum correctly observed that my bike was not a 1972 model but a 1971 (engine number 20M3S15xxx. It was registered originally as a 1972 in the US

It is my understanding that the 71 had a 3 way ignition switch and not the 4 way ?

Kjell - This is an example of the need to assure what is the genuine date of manufacture. Since the 1950s, US car companies sold cars under the system of a "model year" -- it was basically a marketing ploy to beat other manufacturers to the first selling date, thus selling cars at a greater profit. (This was codified by EPA later but was not in force for motorcycles during Commando days).

The "model year" was the specification change point. If Chevrolet wanted to go to a larger engine for 1957, the engine change would be made for the the first "1957 model year" vehicles with production beginning about August, 1956. All smoke and mirrors, but -- since all the 1957 model year cars looked alike and were priced as a group for resale as used cars at subsequent dates, the states in the US identified the specification and manufacturer's designation on registration paperwork by model year -- a designation that looks like a year but only half the cars produced under that designation were actually made in that year. In most states, the manufacturer had to provide a document that listed model year, even if the manufacturer didn't build to the model year scheme.

Norton changed specifications in the Commando era when engineering was completed and on a schedule that was somewhat, sometimes, varied by the fact that motorcycles sell better in the spring and summer than other times of the year. But importers were required to list *something* under the model year designation. So they did but these dates on the registration papers issued by the states (based on the importers' statements) had nothing to do with the date of vehicle build or it's specification. If your Commando has the early-type engine cases, it will have been built to the 1971 specification. Forget about the '72 designation on the papers -- that's misleading; if you order parts for a 72 Commando for your motorcycle, there's a good chance that the parts will be incorrect.

That's just the way that things were back then.

The Blewdy Yaink, B. Henderson, N Carolina USA
 
Sure you were a hero too-but not a magician!

Sure a few hundred volt rated (unprotected) darlington transistor can work. I have done it myself. However unless you have the later added zener stack in parallel (like the boyer) the transistor can go bad if the coil wire fall off and the output transistor gets slamed with high voltage reflected spikes(burn). The out put transistor can eventually die as the boundry has become compromised and it is like thermo nuclear run away...

The final version of both the boyer and rita version had a later transistor updated design with an internal circuit that provided some degree of protection. That is when the AB11 rita went from the single varistor"A' version to the "B" version with the new internal regulator transistor. When that final TO-3 transistor went obsolete it caused the end of the rita production. This was related to me in person by John Carpenter.
Thanks for all the great info and the history lesson.
 
@gtiller.
Another thing I came to think of. Somebody on this forum correctly observed that my bike was not a 1972 model but a 1971 (engine number 20M3S15xxx. It was registered originally as a 1972 in the US

It is my understanding that the 71 had a 3 way ignition switch and not the 4 way ?

Yes, that is correct. The 4 way switch will bolt right on, if you want to have the additional position.

Blewdy Yaink's explanation of how your 1971 model is listed as 1972 is almost correct. During the great depression, here in the USA, many auto makers were on the verge of bankruptcy. Fall and winter were traditional periods of slow sales for new cars. The horrid economic climate made things much worse. The manufacturers asked the US Congress to pass a law to allow them to move the start of the new model year from January 1st to the previous September 1st. This would help them generate car sales during the slow months. After the depression ended, the practice was continued. Many people would wait until September & October to buy the "left over" last year's model cars. These cars were brand new, but because everyone wanted the newest model, the manufacturers would have to discount these cars to sell them. The New model year in September practice did not extend to motorcycle sales.
Until 1975, motorcycle dealers were allowed to list the "last years left over bikes", as new. That allowed them to avoid having to "discount" them to sell that old stock. That is how your bike, manufactured in [probably late] 1971, got titled as a 1972. FYI, many 1971 models do not have the month of manufacture listed on the red certification plate, located on the head stock of the frame. My 1971 is one of them.
Does your bike still have the 1971 short side stand? The mounting lug on the frame for the side stand often would break off. It's one of the few issues on that year. Andover Norton does not sell the old style short side stand. They sell a repair piece to upgrade the frame to the new, longer 1972 & later stand. If you have the newer stand, odds are the old one broke off and was updated. In the USA, most of the country has E10 gasoline [aka petrol]. The E10 plays havoc with fiberglass fuel tanks. Many of them have been replaced with steel tanks. The 1972 models have a large crankcase breather that bolts to the rear of the crankcase. The large hole creates a weak point in the cases. Your engine's breather is located where the camshaft ends in the left crankcase.

Charlie K
 
Having a box full of Rita amplifiers, I haven't needed to avail myself of one of these:
https://www.rexs-speedshop.com/product/new-revival-electronic-ignition-to-fit-lucas-rita-ab11-cases/

Therefore I can't comment on quality. But it's good to know it's available if needed.

However I am using one of their replacement pickups and that works fine.
When I installed my first Rita EI on my wife's Mk III, I noticed that the pick up and reluctor looked almost identical to the same items installed on 1972 & later Chrysler products. Chrysler was the first US auto manufacturer to offer electronic ignition. Not sure when that original design was phased out. I figured, if the pick up ever failed, I'd simply graft a Chrysler unit in. I never had any problems with the Rita. I installed it in all my bikes [1980s]
How did you end up with a box full of Rita amplifiers?

Charlie K
 
Yes, that is correct. The 4 way switch will bolt right on, if you want to have the additional position.

Blewdy Yaink's explanation of how your 1971 model is listed as 1972 is almost correct. During the great depression, here in the USA, many auto makers were on the verge of bankruptcy. Fall and winter were traditional periods of slow sales for new cars. The horrid economic climate made things much worse. The manufacturers asked the US Congress to pass a law to allow them to move the start of the new model year from January 1st to the previous September 1st. This would help them generate car sales during the slow months. After the depression ended, the practice was continued. Many people would wait until September & October to buy the "left over" last year's model cars. These cars were brand new, but because everyone wanted the newest model, the manufacturers would have to discount these cars to sell them. The New model year in September practice did not extend to motorcycle sales.
Until 1975, motorcycle dealers were allowed to list the "last years left over bikes", as new. That allowed them to avoid having to "discount" them to sell that old stock. That is how your bike, manufactured in [probably late] 1971, got titled as a 1972. FYI, many 1971 models do not have the month of manufacture listed on the red certification plate, located on the head stock of the frame. My 1971 is one of them.
Does your bike still have the 1971 short side stand? The mounting lug on the frame for the side stand often would break off. It's one of the few issues on that year. Andover Norton does not sell the old style short side stand. They sell a repair piece to upgrade the frame to the new, longer 1972 & later stand. If you have the newer stand, odds are the old one broke off and was updated. In the USA, most of the country has E10 gasoline [aka petrol]. The E10 plays havoc with fiberglass fuel tanks. Many of them have been replaced with steel tanks. The 1972 models have a large crankcase breather that bolts to the rear of the crankcase. The large hole creates a weak point in the cases. Your engine's breather is located where the camshaft ends in the left crankcase.

Charlie K
Hi Charlie,
Another strange thing I have noticed about my bike is that it has disc brakes up front something supposedly the 71 model did not have. However I have read in another posts that some customer were able to sweet talk the dealer to install the disc brake option also on 1971 models. There is no side stand on the bike only center stand
 
Hi Charlie,
Another strange thing I have noticed about my bike is that it has disc brakes up front something supposedly the 71 model did not have.

Many parts get changed over the years. The seat or at least the cover is not original, silencers are Dunstall type.

It looks as if it has a steel fuel tank which also wouldn't be original if it is?
 
Hi Charlie,
Another strange thing I have noticed about my bike is that it has disc brakes up front something supposedly the 71 model did not have. However I have read in another posts that some customer were able to sweet talk the dealer to install the disc brake option also on 1971 models. There is no side stand on the bike only center stand
Odds are, a previous owner upgraded the front brake. I've done similar. No side stand, because the previous owner didn't want the bike to fall over when it broke. The fix requires welding the new style mounting tab to the frame. Usually done during a restoration or when the engine is removed. Commonly available and not expensive. See

https://andover-norton.co.uk/en/shop-details/15988/sidestand-lug-bracket-welded-assy-06-2593-

Does your bike still have the auxiliary power socket on it? 1971 was the first year for that feature. I find it handy for charging the battery or electric clothing for cold weather riding. It's mounted on the "ham can" air filter front plate, down low on the right. See

https://andover-norton.co.uk/en/shop-details/15933/accessory-plug-and-socket-06-2099-

The link above shows the newer design plastic units. 1971 models came with one made of metal.

Charlie K
 
How did you end up with a box full of Rita amplifiers?
You aquire a lot of 'stuff' over half a century :)
The first couple I bought, then some came on bikes that were used for spares and, knowing I use Ritas, some generous people have given them to me.
I came to electronic ignition when the alternative was (less reliable at the time) Boyer-Bransden, and rather glad I took the Rita route. Joe Lucas (Prince of Darkness) was still a going concern back then and later Mistral Engineering took over so never had to look elsewhere.
 
It is my understanding that the 71 had a 3 way ignition switch and not the 4 way ?
Yes, that is correct. The 4 way switch will bolt right on, if you want to have the additional position.

Just to be clear, it's a 4 terminal switch, not 4 key positions (the 3 terminal switch should also have 4 key positions) as the later switch has a separate additional headlamp (UY = blue/yellow) wire connection to the 4th terminal.
What am I looking at?


The '71 harness (also early 200000 series) doesn't have the (UY) wire so there's no point changing the switch unless the wiring is also modified or the later harness is used.
What am I looking at?
 
Last edited:
Yes, that is correct. The 4 way switch will bolt right on, if you want to have the additional position.

Blewdy Yaink's explanation of how your 1971 model is listed as 1972 is almost correct. During the great depression, here in the USA, many auto makers were on the verge of bankruptcy. Fall and winter were traditional periods of slow sales for new cars. The horrid economic climate made things much worse. The manufacturers asked the US Congress to pass a law to allow them to move the start of the new model year from January 1st to the previous September 1st. This would help them generate car sales during the slow months. After the depression ended, the practice was continued. Many people would wait until September & October to buy the "left over" last year's model cars. These cars were brand new, but because everyone wanted the newest model, the manufacturers would have to discount these cars to sell them. The New model year in September practice did not extend to motorcycle sales.
Until 1975, motorcycle dealers were allowed to list the "last years left over bikes", as new. That allowed them to avoid having to "discount" them to sell that old stock. That is how your bike, manufactured in [probably late] 1971, got titled as a 1972. FYI, many 1971 models do not have the month of manufacture listed on the red certification plate, located on the head stock of the frame. My 1971 is one of them.
Does your bike still have the 1971 short side stand? The mounting lug on the frame for the side stand often would break off. It's one of the few issues on that year. Andover Norton does not sell the old style short side stand. They sell a repair piece to upgrade the frame to the new, longer 1972 & later stand. If you have the newer stand, odds are the old one broke off and was updated. In the USA, most of the country has E10 gasoline [aka petrol]. The E10 plays havoc with fiberglass fuel tanks. Many of them have been replaced with steel tanks. The 1972 models have a large crankcase breather that bolts to the rear of the crankcase. The large hole creates a weak point in the cases. Your engine's breather is located where the camshaft ends in the left crankcase.

Charlie K

Thank you, Charlie, for the additional details. As you mention, there was no standardization (indeed no requirement or definition) in Federal law for model year on motorcycles until US. EPA exhaust emission standards were introduced -- which was past The End in 1975. That left a chaotic web of varying state practice for motorcycle model year.
The kicker is that states required an importer to provide wholesale paperwork (called a "MSO" or "MCO" - the states couldn't be consistent on anything - Manufacturer's Statement (or Certificate) of Origin). This was a document that was generated by the importer that provided the basis for a state to issue the first "title" document. All of this in the 1970s was made more complicated by the fact that there were two different importing companies for Norton in the United States. The states required that these MCOs list a model year. OK, model year would be listed, even though the factory never built to model years (it had been practise in the UK to introduce specification changes in the early spring in order to get motorcycles to retailers for the "selling season" as good weather returned after a winter). And during the Commando days, there was a mixture, here's a matrix:
1968 - First production Commando -- Spring 1968
1969 - First production of "S" Model, limited production of "R" model, changes to Fastback -- Spring 1969
1970 - Intro of Roadster, end of "S" production, no real base-model changes -- Spring 1970
1971 - Spec changes; ignition switch moved from side panel, new harness etc., "SS" and "Hi-Rider added. January 1971.
1972 - New engine cases, twin roller bearings, "Combat" option, Interstate introduced, Fastback phased out - January 1972.
1973 - 850 introduced, 750 phased out. "A" variant for noise control phased in (rare). Spring - 1973.
1974 - Mk2 850, engine updates, changes for exhaust noise control. "A" variant for noise control continued (common) - January, 1974
1975 - Mk3 850 - January 1975.

There was a time when one US importer would "reissue" MSOs to dealers after the beginning of a model year. (Yes, it happened -- INMTU, YK???) That importer was under investigation by the FTC for a period regarding MSOs for another motorcycle brand and entered into a Settlement Agreement stating that they hadn't done anything illegal or unethical before and they wouldn't do it again.

With all this lack of standardization and consistency, I say that registration in the US to "model year" is a "legal fiction" for Commandos. The number on a title means nothing. The only way to describe the equipment build specification from the factory is to list production date -- and expect that many motorcycles in existence today are "bitsas".

(I am familiar with all of this as it was a part of my job duties when I worked for NV Corporation/NT Corporation in Duarte California in 1974 - 76,)

B. Henderson, NC -- USA Norton, Marston Rd 72 - 74, Norton Villiers Corp,/Norton Triumph Corp., California 74 - 76, Shenston Rotary Project 76 - 78.
 
EPA standards for motorcycle emissions were introduced in 1975, but were effective in 1978.

.

Noise regulations were by state initially.

California EPA emission standards for motorcycles were also written in 1975, but took effect in 1978.

.
 
Odds are, a previous owner upgraded the front brake. I've done similar. No side stand, because the previous owner didn't want the bike to fall over when it broke. The fix requires welding the new style mounting tab to the frame. Usually done during a restoration or when the engine is removed. Commonly available and not expensive. See

https://andover-norton.co.uk/en/shop-details/15988/sidestand-lug-bracket-welded-assy-06-2593-

Does your bike still have the auxiliary power socket on it? 1971 was the first year for that feature. I find it handy for charging the battery or electric clothing for cold weather riding. It's mounted on the "ham can" air filter front plate, down low on the right. See

https://andover-norton.co.uk/en/shop-details/15933/accessory-plug-and-socket-06-2099-

The link above shows the newer design plastic units. 1971 models came with one made of metal.

Charlie K

Hi again,

It has the power socket AND on the neck plate it says Sep 1971 which corresponds with frame and engine number.
I guess we can conclude that the correct model year is 1971 and that the paperwork on the bike is wrong.
It seems like one of the owners before ( I dont have the whole history on the bike ) upgraded to disc brakes up front, an upgrade which makes a lot of sense to me. Thanks to all for excellent input as usual from the very knowledgeable members of this forum
 
EPA standards for motorcycle emissions were introduced in 1975, but were effective in 1978.

.

Noise regulations were by state initially.

California EPA emission standards for motorcycles were also written in 1975, but took effect in 1978.

.

Thank you, SS. That confirms my memory (or, more like, refreshes it) for details from 45 years ago. I'm going to bookmark that info -- the intro information isn't available on any government web resource that i can find; the *current* requirement is, but the timelines and data for introduction and subsequent changes are not. There is a similar issue with NHTSA -- I've been trying to find the implementation date for first fit of turn signals for months and cannot find it listed anywhere.

Thanks again, and best wishes.
B. Henderson, NC USA
 
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