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1973 850 commando....

Classic Norton Commando Motorcycles.

1973 850 commando....

Postby keso » Tue Mar 28, 2017 7:23 pm

Hello everyone,Just purchased a completly original 9000 mile time capsule bike..been shed stored for 20 years..we are attempting to "bring it back to life".The tank is fiberglass with 20 yr old fuel in it...whats the procedure on that?I need A right side muffler..i see them on ebay..are they ok to use?Currently has no spark so will follow that circut..but does it need a battery to have spark?Need to rebuild amal carbs..I see numbers 932? 952?..i know these carbs are not prized....are there any tricks??Will need all carb lines replaced..where is a good place for parts?The motor is free but the clutch seems stuck as it will roll in any gear...all systems will need to be flushed..trans,brakes,clutch..etc..Just looking for a little help in getting started...thanks in advance..

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Re: 1973 850 commando....

Postby Danno » Tue Mar 28, 2017 7:34 pm

The tank will make a good shelf ornament. Likely as not that old gas is somewhat homogenized with some of the old 'glas resin inside the tank. To be able to use ethanol-laced fuel, you'll need a metal tank.

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Re: 1973 850 commando....

Postby Rohan » Tue Mar 28, 2017 8:13 pm

Danno wrote: To be able to use ethanol-laced fuel, you'll need a metal tank.


And a 73 850 should have come with a metal tank, so someone has done a swap....

Amals left standing always gum up in the jets and idle passages and in the float bowl
and maybe the fuel tubes and filters..
A really good clean or 6 should have it idling like new (!!),
or at least you'll be able to assess how worn they are.

A known good battery would help in testing/checking a bike thats been standing for years.
Don't forget that Commandos are POSITIVE EARTH, they hate having the battery wired in backwards...

Have fun !

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Re: 1973 850 commando....

Postby keso » Tue Mar 28, 2017 10:09 pm

wow..thanks for the quick replys...i beleive the bike is all original..1 owner..so you think the tank is not original?...didnt the 73s come with fiberglass?...i am going to learn all I can before we start...how can I tell if tank is shot?

keso
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Re: 1973 850 commando....

Postby Rohan » Wed Mar 29, 2017 1:02 am

An early 850 might have had a fibreglass tank, but somewhere in 1973 (I think it was ?) it was mandated that all fuel tanks had to be metal - or couldn't be fibreglass, not sure precisely how it was worded.
LAB (moderator) is the hexpert on this, will probably say, seems to have this stuff at his fingertips.

Glass tanks don't seem to like modern fuels, depends on where you live, even without ethanol.
Once you see the bubbles in the gelcoat, its shot. And no longer safe...

Examine carefully all the rubber components on your bike. Including the tyres.
It takes a very favourable climate to keep those all in good usable condition.

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Re: 1973 850 commando....

Postby L.A.B. » Wed Mar 29, 2017 1:35 am

keso wrote:Currently has no spark so will follow that circut..but does it need a battery to have spark?


If it still has a (working) 2MC capacitor (see factory manual link below, section J24) and the original points ignition (as it's been laid up for 20 years?) then theoretically, it should spark/start without a battery.

http://www.classicbike.biz/Norton/Repai ... mmando.pdf



Rohan wrote:And a 73 850 should have come with a metal tank,


Well, "should have", unless it's a Hi-Rider.


Rohan wrote:An early 850 might have had a fibreglass tank, but somewhere in 1973 (I think it was ?) it was mandated that all fuel tanks had to be metal - or couldn't be fibreglass, not sure precisely how it was worded.


Fibreglass tanks were banned from July 1973 (motorcycles manufactured for the UK market, existing F/G tanks were still legal to use).
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Re: 1973 850 commando....

Postby concours » Wed Mar 29, 2017 6:42 am

keso wrote:wow..thanks for the quick replys...i beleive the bike is all original..1 owner..so you think the tank is not original?...didnt the 73s come with fiberglass?...i am going to learn all I can before we start...how can I tell if tank is shot?


Hi, welcome.
If you tell us a bit about your skill set, it'll be easier/faster/more accurate to help you. Also, if you fill in your profile (location) , we can help you better.
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Re: 1973 850 commando....

Postby 1up3down » Wed Mar 29, 2017 7:55 am

pictures

we need lots of good ones

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Re: 1973 850 commando....

Postby keso » Wed Mar 29, 2017 11:08 am

Thanks...I will update profile and get pics....

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Re: 1973 850 commando....

Postby N0rt0nelectr@ » Wed Mar 29, 2017 11:44 am

Rohan wrote:
Danno wrote: To be able to use ethanol-laced fuel, you'll need a metal tank.


And a 73 850 should have come with a metal tank, so someone has done a swap....

Amals left standing always gum up in the jets and idle passages and in the float bowl
and maybe the fuel tubes and filters..
A really good clean or 6 should have it idling like new (!!),
or at least you'll be able to assess how worn they are.

A known good battery would help in testing/checking a bike thats been standing for years.
Don't forget that Commandos are POSITIVE EARTH, they hate having the battery wired in backwards...

Have fun !


I bought a 73 Norton years ago for $500 because the owner had it set up for negative ground. I had to replace about 6 ft of ground wire and buy a new battery. Sold it a few years later for a lot more than I paid.

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Re: 1973 850 commando....

Postby keso » Wed Mar 29, 2017 6:40 pm

Ok,I have alot to learn!....SOOOO positive to ground..what a CONCEPT!...My skill set seems to be to aquire good deals..they seem to pile up..I can do some work but have a friend who does it all..he has the bike now..but its his first brit bike..so hes taking it slow..want to try and salvage the tank as its not leaking and has had gas in it for 20 years(caswell sealer?)..oil tank was nearly empty..cant get master cyl cap off..but not trying real hard..dont want to twist off the casting!I live in minnesota.....need parts like airbox,1 muffler,2 petcocks,1 amal bowl(broken at bottom hose,carb kits..tires,....where do you guys find the parts? ebay?...will get pics up when I review the procedure..where do I look to review pic procedure??.thanks all

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Re: 1973 850 commando....

Postby Ekvin » Wed Mar 29, 2017 8:33 pm

Congrats on the Commando!
Procedures for posting pics is at the top of the Topic page titled "Technical Information and How to Post Photos".
As for parts there does tend to be some on ebay but likely you will need some new parts from a parts dealer.
http://www.britcycle.com/
http://www.classicbritishspares.com
http://www.oldbritts.com/
https://andover-norton.co.uk/en/shop/
coloradonortonworks.com/catalog
http://www.norvilmotorcycle.co.uk/
http://www.walridge.com/catalogue/

I'm sure there is more. I have ordered parts from British Cycle and Walridge as they have shops in Canada, both have been excellent.

Cheers!

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Re: 1973 850 commando....

Postby Rohan » Wed Mar 29, 2017 9:51 pm

keso wrote:..oil tank was nearly empty.


The oil will have drained down into the sump.
(Brit bikes do that !).
Be sure to drain it out before adding more oil to the oil tank.
Or you will have tooo much oil, and an unholy mess...

If its nice and clean you can add it back into the oil tank.
But after sitting 20 years, new oil would be a very good idea.
And a new filter (unscrew it from behind/under the gearbox).

Your pics need to get posted to one of the free photo hosting services,
like photobucket, and you just post the links here.

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Re: 1973 850 commando....

Postby Mr. Rick » Wed Mar 29, 2017 10:54 pm

I found the same type of bike several years ago, have a few suggestions:
Search this site to find out which supplier (one of the sources from India, I think) sells the best steel tank, and quit worrying about what kind of gunk is coming through the fuel lines and into the Very fine passages in the carbs. The tank is not very expensive, although the painting probably will not be cheap. If your sidecovers are in good shape, send all 3 to Vintage Vendor vintage-vendor.com where he can match your existing color, if that's what you want.. Or do a beautiful metalflake job!
Buy 2 new mufflers and don't worry about why one side is showing less back pressure. Get a recommendation from somebody here regarding which silencers are the better ones.
Get a brand new sealed battery.
Carbs are 932. 32mm. Plan to physically clean the pilot circuits. http://www.jba.bc.ca/Bushmans%20Carb%20Tuning.html
Positive ground, yes. Most ground wires are red on the original harness, I believe.
You will probably want to ditch the "points" ignition and the ballast resistors, and condensers, in favor of electronic ignition, unless you are devoted to spending a lot of time fiddling with the original system. The new systems are almost invisible, set and forget, very much an upgrade.
The original master cylinder is not a good match for the caliper, bored too large. Consider getting the one from Andover which looks exactly like stock and is sized correctly, or buy a sleeve kit from Don : http://www.tritonmotorcycleparts.com/29 ... line-store
My BAP petcocks have worked perfectly for years.
I dropped my stock air filter in favor of the K & N R-0990, got fed up scraping the paint off the frame every time I went in there.
I'm in California and use FAir Spares for parts. Phil is a genuine expert and always takes the time to help or explain things.

Hope you have as much fun, and get as much satisfaction, as I have over the years!
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Re: 1973 850 commando....

Postby keso » Wed Apr 05, 2017 8:40 pm

thanks, for the replies...i am still waiting on a few parts...and was wondering..my bike is a 1973 850 commando...whats the difference between interstates...roadsters...was there ever a super commando?..I remember hearing about it in my youth...I will get pics up but the bike is sitting for now as we get parts...Still looking for a stock airbox and cleaner..where to purchase the fuel line...is it worth it to upgrade the floats and needles?

keso
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