1973 Norton Commando

Discussion in 'Old's Cool' started by rudolf35, Jan 25, 2012.

  1. Steve G.

    Steve G. Long timer

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    West is the Best

    IMO, the best of the Nortons,,,,,late 750's, and all right hand shift 850's. You've been given many great pointers. I will list some of this particular machine's weaknesses, which you can look at later or right away.
    1] The upgrade to some form of electronic ignition really is a no brainer.
    2] The isolastic engine/gearbox suspension system really does work well at isolating the incredible vibration of this engine,,,,which started out as 498cc. The original rubbers will now be getting tired if original, and a perfect time to upgrade to the Mk111 850 system which allowed for quick and easy 'vernier' adjustment instead of the tiedious and time consuming old system which all Nortons had except the Mk111 electric start models.
    3] The swingarm bushings are in fact oil bushings, not grease bushings. And the system is sealed with o-rings. And they leak. So get used to it, you will have to get some 140 weight oil in there or the bushings wear out quick.
    3] Amal carbs work very well on these engines, and they look 'right' on them. I certainly can understand upgrades in this area with a single Mikuni for an example. I'm a bit of a traditionalist in the visual aspect of all my machines, and this is one upgrade I won't do, stricktly on visual. that said, Amals have a hard life bussing away on the end of those solidly mounted intake manifolds, lifespan around 10-15,000 miles, where slide/body clearances open up. This essentially causes one issue, upward creaping idle rpms whilst sitting at a stoplight. Once on the road, you won't notice a difference.
    4] A big problem with the Mk111's [Portugese bearing supplier], but also an issue with the others,,,,the gearbox layshaft bearing is under-qualified to handle the tourque of this engine package. As mentioned, the telltale sign will be the kick starter starting to shudder downwards while accelerating from a start in first gear. If not changed to the upgrade 'mini superblend' bearing, this can cause complete rear wheel lockup as the kickstarter goes down far enough to hit the exhaust.
    5] Exhaust nuts,,,,keep them tight. Tighten them while the engine is hot.
    6] As mentioned, avoid fibreglass tanks totally. Ethanol kills them. There were actually two tank options for '74, not counting the Highrider or the JPS. The standard steel Roadster tank, and the Italian made 4 1/2 imperial gallon steel Interstate tank. There is a distinct visual difference in width to the later 5 1/2 imperial gallon English made steel tank, or the huge 6 gallon plastic tank. The only drawback with any Roadster tank is range, probably 100-115 miles before reserve hits. Interstate tanks have a disadvantage in that the tank is 2 1/2" longer, forcing the rider back, while the footrests are not. This causes the rider to become a human kite at highways speeds. luckily, several manufacturers have rearsets to turn this situation around.
    7] 1973 and later Commandos will have indicators as standard. Unfortunately, the indicators are self grounded through the chrome plating on the inside by the light bulbs, and the improper grounding is somewhat common.
    8] High quality upgrade kits to the charging system are available, including eliminating the zener diode heat sink, fragile bridge recifier and single faze stator. And the magnets on the rotor will be getting tired now.


    Steve
    #21
  2. rudolf35

    rudolf35 Warped & Twisted Mind

    Joined:
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    797
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    Arlington, TX
    I have been getting some very good pointers!

    Now, the only thing I need is for the seller to send me the images. I nugged him again and see what happens.

    :ear
    #22
  3. BrianK

    BrianK F'in' half ass lookie boy

    Joined:
    Dec 29, 2008
    Oddometer:
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    Location:
    Boston, Manxachusetts
    I wrote the following to another poster who, some time ago, inquired whether he should buy a Commando:


    If you buy that bike, I predict:

    - You will find many, many things that need to be fixed/replaced, no question about it. Tires, battery, cables, fluids, probably a bunch of seals and gaskets, layshaft bearing, etc.

    - You will find many, many things that you could probably live with, but want to improve and bring up to a better standard of performance. Brakes, wiring harness, H4 headlight on relay, electronic ignition, clutch pushrod seal, chain and sprockets, carbs, etc.

    - You will find that the dollars you put into the bike AFTER you buy it at least equal its initial purchase price. Soon. And then they exceed it.

    - You will need to purchase a slew of special tools to work on your bike - whitworth sockets and wrenches, clutch removal tool, primary chain sprocket puller, points seal tool, exhaust nut tool, etc. (If you DON'T work on your own bike, you will find you bought the wrong bike.)

    - You will spend a lot of time on this board and other Norton resources (of which, thankfully, there are plenty) seeking answers to a lot of questions about how to fix your bike.

    - You will find yourself very frustrated by the bike and its quirks, on a regular basis.

    - You will find that at some level you really enjoy all of the above. You will not admit this to anyone else.

    - You will find that you love your Commando far more than you would ever have believed, and you wouldn't be without it for the world.

    - You will thank your lucky stars you decided to buy your Commando. Then, another problem will arise... but you will deal with it and it won't change your mind about the bike. <!-- / message -->
    #23
  4. lemieuxmc

    lemieuxmc Banned

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    3,360
    Location:
    East La Jolla... it's just Clairemont!!
    Shit... just wait till you have a Commando, a Guzzi, a BMW with chair and a Suzuki DR650.

    Hell... when I open my garage door I'm more confused than a toddler in a titty bar! :lol3

    Attached Files:

    #24
  5. lrutt

    lrutt SILENCE.....i kill you

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    What hack is that?
    #25
  6. yokesman

    yokesman Been here awhile

    Joined:
    Sep 12, 2008
    Oddometer:
    557
    email me at richardlstrain@g.mail.com give you some unwritten pointers.
    rode mine during college, 60-100 miles daily.One kick bike, won many dollars after starting and betting they could not do it.
    #26
  7. RobbieO

    RobbieO Muskokatard

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    Dumpmere - Muskoka
    The Corbin seat made a big difference!

    [​IMG]
    #27
  8. Doug Matson

    Doug Matson Long timer

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    Torrance, Ca.
    Speaking of the layshaft bearing, here is what mined looked like with no warning.
    [​IMG]
    #28
  9. Steve G.

    Steve G. Long timer

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    Portugese bearings,,,,oh yeah. port yes, anything else, no.
    #29
  10. victor441

    victor441 Long timer

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    there is an excellent Commando forum at http://www.accessnorton.com/ good people and info on all repairs, upgrades, etc. Have a '73 850 myself and it is a great bike also waaay more reliable than the '69 750 I rode long ago
    #30
  11. lemieuxmc

    lemieuxmc Banned

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    Location:
    East La Jolla... it's just Clairemont!!
    That's a Velorex that I reinforced the frame, built the mounts for, and stiffened up with wooden ribs inside, to make it strong enough to open up the cockpit and accomodate a really big cooler for my "Sidecar Soda Service" vending business.

    A nice side effect is that my wife likes riding around in it (slow and easy roads) because it's not claustrophobic.
    #31
  12. lrutt

    lrutt SILENCE.....i kill you

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    I thought it was a velo. I have on on a CB750 Honda but it's so damned hard to get in and out of. I'd likely not open it up that much but at least some. Interesting.
    #32
  13. Lomax

    Lomax Nanu-Nanu Adventurer

    Joined:
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    I just picked up my second 73 commando and found this old thread. Looks like I will be doing swing arm bushings and front brake resealing at least.

    A book is on the way. If anyone has good advice on the swing arm bushings and front brake, like tips or places to find parts, it would be greatly appreciated.

    My old 74:

    [​IMG]


    Hopefully the new 73 will come out even better.

    Marc
    #33
  14. concours

    concours WFO for 41 years

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    Most likely it's the swing arm PIVOT SHAFT wobbling in the engine cradle causing the movement. Learn about the Kegler mod, http://www.accessnorton.com/heinz-kegler-clamp-and-oil-line-routing-t17855.html?hilit=kegler#p223153


    www.accessnorton.com has a lot of good info. www.oldbritts.com is a premier (AWESOME service, stock, quality) parts supplier.
    #34
  15. Steve G.

    Steve G. Long timer

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    I've had my 11/73 Commando Interstate since 1988, and also have a '72 Combat that's been in the family since 1990. It has been said that the 850 right hand shift Nortons are the best of the Commando's. Not really the most collectable, but by far the best daily driver, most reliable, and nicest most happy engine. The 850 really has it all compared to all other English twins pre: 1990. It's got proper head cooling, proper oiling, and with the superblend mains as standard, the bottom end virtually unburstable.

    As has been mentioned, everything is still available for them [heck, Les Emery still sells new versions of the Mk11a new in England] and the modification potential in all aspects is endless,,,,brakes, ignition, charging, carburetion, power, handling,,,all can be vastly and easily improved. It's still a great bike left bone stock, with just slightly more regular attention than a Japanese bike of the same era.

    The biggest weak points of the early 850's were the continued regular checking of the isolastic points on the bike. Left on their own, the Norton show's why it got it's nickname [bender] as loose iso's may make the engine smoother, but will get wobbly in time. Changing to a Mk111 isolastic system is a move many make. The charging system may be getting lazy, most as the magnatism of the alternator rotor will have weakened, with it the charging output. Carburerator life suffers hanging off an 829cc virticle twin. The slides loosen in the bores, and indicate this issue with a creaping idle sitting at a traffic light as they slowly rattle up. Not a bad problem, but new improved Amal Concentrics are quite cheap and easy to get fully jetted to your bike and altitude, why not? Swingarm bushings can be buggered by owners who don't know that they are lubricated with very thick gear oil rather than grease, complimenting the Norton's "bender" monicker.

    They are enduring classics, buy one and enjoy every ride, huge pride of ownership will result.
    #35
  16. ricochetrider

    ricochetrider a certain something

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    There are more than a few upgrades and modifications for the 850 Commando.
    As mentioned, the head steady is among them, also a ball valve mod in the lower end to prevent wet sumping is popular and effective. Mine (1974) has a dry clutch, primary belt drive, a single Mikuni carb, & both the above mods, among others. Runs like a beast, and steady as a rock.

    There are at least a couple real Norton experts, a bunch of good people, multiple sources for parts etc, and tons of good info available at BritBike.com. Here's a link to their Norton forum pages.
    Please do check them out. They are a great go-to for any Britbike owner or fan. Awesome site with really great members.

    http://www.britbike.com/forums/ubbthreads.php?ubb=postlist&Board=3&page=1
    #36
  17. Brad-Man

    Brad-Man Adventurer

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    Marietta, GA
    Just for my information, what is it about the '75 850's that downgrade them as opposed to the right side shift bikes....
    #37
  18. norton73

    norton73 drinkin'

    Joined:
    Dec 20, 2003
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    Location:
    Beautiful Downtown Springville, Alabama
    5 or so years ago you couldn't give a '75 away, now they are climbing in value and desirability.

    The things that people didn't like about them are the things that make them desirable now.

    They weigh more, due to the electric (non) starter, a little detuned from the earlier bikes, and the added complication of the crossover for the left side shift.

    Now, as the riders get older, they want the electic start (there are mods that will make it work), and if they own modern bikes, don't have to remember how to shift.
    #38
  19. ttpete

    ttpete Rectum Non Bustibus

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    Join the International Norton Owners Association (INOA). Then seek out and join your local chapter. A great bunch of folks, the national rally this year was in Wyoming. Then get a copy of their technical book. It's in its third edition and has just about got everything covered through the collected wisdom of the membership over the years.
    #39
  20. norton(kel)

    norton(kel) vintage

    Joined:
    Apr 13, 2010
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    Location:
    CO.
    Due to the original posting date of this thread I hope the OP has been enjoying his Commando for the last two years:lol3
    #40