73 850 questions

Hi, I bought a 73 850 Commando last year with the top end in boxes. I've built up a collection of Hondas from 69-82, many from real junk so I know my way around Hondas. So, it was time to "move on" and the Commando was an easy choice. I've sent for Hemmings DVD and I'm trying to track down info.

Unfortunately my VIN 306285 isn't covered by Andover so I can't get the despatch info. And to make things "interesting", our local MVA registered the bike as a 750 but it isn't, at least not now. It does not have studs and nuts all around the base of the jugs so that's that. I bought the bike thru a 3rd party so I've yet to speak to the PO, whose family have owned the bike since new. So forgive me but I've got a few questions:

Can anyone confirm for me for sure that 306285 would be an 850 for sure and if so would it be a MK III or ?? How would you know? I.E. what reference is out there? :shock:


I've got the bottom end in the chassis and all protected from the weather while my new building is under construction. I don't want to start unwrapping it - the side cases are off both sides - where would I find the engine number? :?

The head appears to have been done and I found old valves etc, also old pistons and rings, so some work has already been done for sure. I'm hoping to be put in touch with the PO soon, which may unlock some mysteries or make things worse! :roll:



I will be doing a thorough frame up review of what's there, engine mounts, steering head bearings, swing arm bearings, real basics like I do with the Hondas. I intend to upgrade the fork internals (I read there's cartidges that can be installed), and a good dual disk setup - As a system from master, SS hoses, DOT5, calipers, pads & rotors not just fancy rotors and maybe a new master on ratty old hoses!

Let's see.. new carbs to replace the old Amals which I have and could rebuild (suggestions? flat slides?), I need suggestions for electonic ignition, and I hate to say it but with severe back injuries I should consider electric start conversion (I know, frickin burn me at the stake!). So you see where I'm headed, a resto-mod, no horsepower junky, safe & reliable.

So please, hit me up with any info and suggestions, links etc. that you can think of.
Thanks mucho beaucoups in advance! 8)

d9canada said:

Can anyone confirm for me for sure that 306285 would be an 850 for sure and if so would it be a MK III or ?? How would you know? I.E. what reference is out there?

Click to expand...

850s were 3xxxxx.

306285 would be a late 850 Mk1.

There is also likely to be a non-matching *850*F1xxxxx* frame number stamped on the RH side of the headstock next to the certification plate.

Welcome!

According to dynodave's list, with those s/n, your bike would have been manufactured between April-Nov '73.


http://atlanticgreen.com/commandoframes.htm

Engine number should match frame number, unless motor has been swapped out. It is on the top of the engine case left (Primary drive) side right under the barrels. Note that the "side cases" you have off are the primary, tranny and points housing covers.

You will need a manual - Factory workshop manuals, parts manuals, riders handbooks and more: http://britmoto.com/

or online version - http://rocbo.net/technique/norton_workshop/004.html

Commando Workshop Companion has good tips and pics - http://www.doov.com/apps/nortoncompanion/

AS does Old Britts (and great for parts)- Technical Information from Old Britts: http://www.oldbritts.com/ob_tech.html

You want eye candy and cools parts to buy?

http://coloradonortonworks.com/
http://www.tritonmotorcycleparts.com/29 ... line-store
http://www.jsmotorsport.com/

Some other handy links are here:

technical-information-t2357.html

Ask the P.O. famdamily if the layshaft bearing was ever changed out. Important safety issue.

Thanks everyone for the fast replies. L.A.B. you're right, July 73 to be exact, and Torontonian, I'll certainly check out - sounds like "there be serepents!" I'll check for the F Frame stamp again but I didn't notice it earlier today.

And gortnipper thanks, I've made a whole new links folder full of stuff. Nice to see Oldbritts is close by for once and not 3000 miles away! Just one thing, I drove in right away for a manual download from Britmoto but the 850 manual is for the MkIII electric start 1975 VIN 325001 and on. My bike is a 73 VIN 306285 (Rats! I thought it would be just like the PDFs for my Hondas.) Any idea where I can get a MkI manual in PDF format?

Lastly, early on this journey I read somewhere, maybe Wiki, about the generations of 850 - the differences, but of course now I could use a 'over there dummy!' push in the right direction.

Thanks again, this has been a big help.

Quick edit, forget my question about britmoto - the early 850 info is under 750, I should have looked a bit harder first, sorry!

d9canada: I have an extra parts list and extra shop manual, both with 1973 copyright dates, in separate binders.
Send me a private message with yr address if you want them, no charge.
Don Pender in the Philippines http://www.tritonmotorcycleparts.com/297620484 has a lot of good stuff for improving the Commando, including brakes, and a Sweet fork conversion kit called the Lansdowne damper kit. I haven't seen any other cartridge kit for the forks that I'd consider installing on my bike. He's also on this forum as madass140.

Thanks again Everyone, I didn't expect to so quickly have access to hardcopy and electronic versions of manuals etc. and pretty much all the information I need. There's just one thing. Don't you love it when a new guy says "I just need to know one thing" ?

Can anyone point me to information explaining clearly about the development history of the 850 from the Mk I that I have to the later Mk III, please. Like I'm aware of the electric start but I'm assuming there are other things, some of which might work as upgrades to the Mk I and some not. I need to come up to speed on all this.

For example, I never even hear of a Mk II but maybe I just haven't been around long enough. I want to know what parts or systems were upgraded or altered between Mk I to Mk III so I don't buy something that won't work, or conversely, buy an older version if I should consider buying a newer version if a Mk III part or system can be added as an upgrade.

Don't know about 850 mk1 to mk2, but here are mk2 to mk3

mk3-changes-from-models-t21935.html

d9canada said:

Can anyone point me to information explaining clearly about the development history of the 850 from the Mk I that I have to the later Mk III, please.

Click to expand...

In brief:

850 Mk1 produced as Roadster, Interstate and Hi-Rider models, from serial number 300000, March '73. An 828cc version of the existing 750cc Commando (750 MkV by '73) but with stronger 'through-bolt' cylinder block (silver for '73), balanced exhaust and different steering geometry.

http://www.classicbike.biz/Norton/Broch ... LineUp.pdf

306591, 850 Mk1A introduced as a 'low noise emission' variant intended for the European market, with annular discharge 'black cap' or 'bean can' silencers/mufflers and large plastic airbox.

307311, 850 Mk2 (upgraded Mk1) and Mk2A (upgraded Mk1A). Can be considered the '74 models, the Mk2 mainly sold in US/Canada and Mk2A sold in Europe although some Mk2As were eventually sold in the US.

http://www.classicbike.biz/Norton/Broch ... ochure.pdf

325001, 850 Mk3, the '75 model, electric start, rear disc brake, left foot shift, automatic primary chain tensioner, 180W alternator, front disc now on the left, ignition switch in a console with warning lights between the speedo and tach, redesigned switch clusters, hinged, lockable seat, vernier Isolastics.
All Mk3s had the annular discharge 'low noise' silencers and black airbox.

http://www.classicbike.biz/Norton/Broch ... LineUp.pdf

like you, I have a 73 850 Mark 1

the "Mark" stuff just means that particular build model for that year, in 73 the 850 was called a Mark 1, in 74 a Mark 2, and in 1975 a Mark 3

please state where you live, city, state, country as there may be someone one the forum who lives by you and could be of tremendous hands on help

you are embarking on a great journey, lovingly restoring the best twin to come out of England, ask all questions on the forum, everyone wants to help you

I am 67 now and after four spine surgeries can no longer kick start my Norton and so I installed a push button electric start for around $2700, worth it to me

I order lots of goodies for my Norton from Coloradonortonworks.com, I have their TriSpark electronic ignition, single 34mm Mikuni carb kit, hydraulic clutch,
complete modern Brembo front brake conversion, CNW Head Steady to replace the stocker, all new wiring components, etc etc

WELCOME to the wonderful, sometimes exasperating and always entertaining world of Norton Commandos !

Hello d9,
I also have a 1973 mk1 850, an Interstate. I've owned it since 1975 and have done a few mods on it during that time. I stripped it all down to repaint the frame a couple of years after buying it because the original factory frame paint was very poor and flaking off!
I fitted Boyer electronic ignition very early on and also sleeved down the front brake master cylinder with an RGM kit.
I fitted a 3 phase 180watt alternator many years ago, also converted the system to negative ground so that I could fit a modern electronic flasher can (which doesn't rely on battery voltage to control the speed of the flashers.)
I have changed many of the fixings for stainless and also made up some stainless rear footrest and exhaust hanger plates.
I don't ride it all the time as I have other bikes too, also still working as a self-employed domestic electrician so don't get a great deal of time although I do plan to start using it more often, I am 72 now and feel that as i'm lucky enough to still be able to manage to kick start it I should me making the most of my fortunate good health!
I am toying with the idea of doing a single carb conversion now, I will stick to the Amal mk1, just need to order up a manifold. I don't think it will affect the performance a lot, it will only limit the top end a bit and we're limited to 70mph here in England anyway! I do get a bit fed up with regularly re setting the carbs etc.
Another mod I have done is the fitting of a shut-off tap in the oil supply to prevent wet-sumping (as I don't use it enough!) I have fitted an ignition interlock switch to this so there's no chance of starting with the oil switched off.
Good luck with your project, it will give you hours of fun i'm sure!

Dave.

Two things you will run across often is the Mk3 isolastic adjusters and the swing arm spindle. Variations on both are considered upgrades to earlier bikes but need a little study before being put into use on your Mk1. You can study parts groups on the Andover Norton web site or at Old Britts to compare years and check part numbers.

gortnipper said:

Don't know about 850 mk1 to mk2, but here are mk2 to mk3

mk3-changes-from-models-t21935.html

Click to expand...

Don't forget the Mk2A models!
John in Texas

Re: 73 850 questionsbadly bo

Wow! Thanks so much everyone! My big fear with tackling the Norton was I'd heard of quirks and quality control issues that I figured were the sort of thing that you only learned by knowing through years of being in contact with people who know some guru.
Heck I spend more time on Honda forums watching posts from guys who are clearly guessing but feel compelled to post stuff is likely to cost someone time or money.
I have DVDs coming from Hemmings, downloaded manuals and parts lists but have hard copies on the way too, and I managed to contact a brother of the PO who confirmed a new trans cluster, head rebuild & pistons/rings are fitted since the tear down, and the 8000 miles indicated is true. The brother I spoke to, had purchased the bike new and mentioned it's banana seat, which I did not get, so I guess this bike was originally a Hi-rider (I hate those things!) All I have is a Bondo'd peanut tank. Ha! It will be fun!
Thanks again!

Did the new cluster include a new layshaft bearing ? Important stuff .