Newbie in for advice!

Hi guys!
I'm located in Europe, and I'm very happy to become part of this awesome community!
I dreamt of owning a Commando since I was a child... Now I have to get one.
As I was younger, I never really thought it through, which Commando to buy. 750, 850, early, late... No idea.
Now that I'm looking for my ride, it became an important point.

This week I'll have a look at a '73 850 Roadster MK1 (not the -A version) and an early '70 750 Fastback (Frame Nr. 1351XX).
I can't fathom if the Fastback is a '69 or a '70 model, since it has no Norton imprint on the timing cover but black painted cylinders and upswept peashooters. No idea what happened there.
I love the Fastback, but I'm scared of having such an early 750 motor...
The more modern 850 engine gives me a little more peace of mind.

I hope I'm not restarting an old discussion that you don't want to see anymore.
Just asking, is an early 750 a source of continuous problems?

Thanks a lot guys!

Welcome, cappo.

cappo said:

I'm located in Europe,

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"Europe" is a big place. Would you care to be a little more specific? :wink:

cappo said:

I can't fathom if the Fastback is a '69 or a '70 model, since it has no Norton imprint on the timing cover but black painted cylinders and upswept peashooters. No idea what happened there.

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Does the engine number match the frame?
Does the number have a '20M3' or '20M3S' prefix?
1351XX would be (approximately, March) 1970 production, so it should have the Norton logo on the timing cover with the camshaft-driven points assembly and timing side crankcase (rather than external timing cover) rev counter drive.

cappo said:

Hi guys!

I hope I'm not restarting an old discussion that you don't want to see anymore.
Just asking, is an early 750 a source of continuous problems?

Thanks a lot guys!

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It's true to say that like any other bike, the Commando was improved as time went on, so in general terms, the later the model the better it was.


I've had a 750 that was used on the racetrack for many years and is now my road bike. Throughout the years people have told me it would blow up any minute, but it hasn't and I put it down to careful preparation.

I have had the crank balanced and the conrods and pistons. The pistons are 0.1 grams different as are the conrods and I even weighed the big end bolts when I replaced them. ( They can be a gram different)

The 750s have been known to crack the lower flange off the cylinders but I have found in my years of racing that the base gasket compresses and the bolts loosen which I think could be a cause. I now use a copper gasket from Jim Schmidt and that problem has gone away.

There were issues with Combat models and reliability ( plenty of info on this forum) but otherwise I'd have no problem running a 750 as a road bike.

Sorry L.A.B., saying Europe really wasn't specific enough I'm in Switzerland.
I'll put my location in the profile as well, I forgot

I don't know much about the bike, yet. :?
I'll call the owner later today and ask him about the discrepancies.

In this picture, you can see the bike, and some of the engine. I guess that's a rev counter drive on the timing cover... Isn't that wrong for a '70?


pommie john, I read a lot about the reliability problems with the combat engine... Right now there is no '72 750 on the market over here, so that question does not arise! What year was your 750 racer?

cappo said:

In this picture, you can see the bike, and some of the engine. I guess that's a rev counter drive on the timing cover... Isn't that wrong for a '70?

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It would be wrong for 1970, so it seems the engine has been replaced with an earlier '68 - '69 '20M3' unit, however, the bike seems to be in good condition so I wouldn't let the change of engine put you off buying it if the price is right.

cappo said:

pommie john, I read a lot about the reliability problems with the combat engine... Right now there is no '72 750 on the market over here, so that question does not arise! What year was your 750 racer?

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It's a combination of many years including some Atlas parts!

Looks also like a single carburettor conversion and an anti wetsumping device in the oil line. Where in Switzerland do you live? I am from Ravensburg, Germany

Guys, thanks a lot for your time!

L.A.B., I really like the bike and it seems to be in very good nick.
You can probably imagine, since I was scared of a 1970 engine, how scared I'd be with a '68-'69 20M3!
Reading about the early bikes, I thought it may be a '68 bike which got a new frame (with new frame number) in 1970, since the early frames used to break?
Or did those bikes get a new frame retaining the old frame number?
I guess the lack of matching numbers impacts the value of the bike pretty badly!

Rivera, I have no idea how you could see the conversion from that picture! Respect!
I really can't see it
By the way, I live in Saint Gallen since 2011. And since my girlfriend lives in Friedrichshafen, I'm often on your side of the lake :mrgreen:

cappo said:

Reading about the early bikes, I thought it may be a '68 bike which got a new frame (with new frame number) in 1970, since the early frames used to break?
Or did those bikes get a new frame retaining the old frame number?

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A new replacement frame wouldn't normally have a number, so it probably isn't a '68 that has been 're-framed'. The original gearbox casing would also have been stamped with the same number as the engine and frame so that is something to check.

cappo said:

I guess the lack of matching numbers impacts the value of the bike pretty badly!

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This very much depends on whether it is being bought primarily to ride, or as more of an investment.

I wouldn't let the 750/850 issue be about reliability or 'betterness'. I would rather question how you like to ride, the 750 is more nimble and the 850 is more of a cruser. Either one can be made to run reliably. But the early engine in the F/B would bother me somewhat too. Remember, you don't have to buy something just because it's for sale now. There's always more coming along. It's up to you.

cappo said:

Rivera, I have no idea how you could see the conversion from that picture! Respect!
I really can't see it

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I found the add in the internet.
The bike is not 100% original. As mentioned a conversion to a single ( Mikuni?) carb.
The rear chainguard is wrong, the rev counter is not the early type without the red quadrant.
The exhausts are the later style peashooters.
And then the engine issue...
Before you buy it, talk seriously about the price!

It looks clean and the conversion to single carb is not bad.
Depends what you are looking for. An original machine or a good rider.

I have restored a 1970 Commando "S" and except for some electric gremlins it is a fine bike.
This summer I helped a friend with his 1969 Commando Fastback he bought
and his engine sounds even mechanically
calmer than mine.
These early Commandos are more "snappy" than the later 850 machines.
But you cannot expect a " push the start button and go" bike like my 1963 BMW R 75/5.

There is a "Engländer Stammtisch" every second Friday of the month in Salem/Baden in the "Biker´s Inn".
We meet actually this Friday.
On Sept 16-18 there is a british bike meeting also at the "Biker´s Inn".

rivera said:

the rev counter is not the early type without the red quadrant.

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I wouldn't expect it to have a rev counter without the red zone if it is a 1970 model (135XXX).

Well, I'm used to very snappy modern bikes, my last one was a Buell XB12...
Maybe a 750 is the right choice for me, since I'm not planning any long highway sessions with the bike.
Is the difference really that big? How come the 850 gets as much love as the 750 then?
Or at least so it seems to me!

As it looks like, the red Fastback got puzzled together... It's not gonna be an investment, but I'd like to have a nice example.
I'll keep looking, there is no pressure... Well, winter is coming :lol:

In the meantime I found a 1970 750 roadster, its frame is numbered 1382XX. I just love that front drum brake
It looks ok, even if in need of some TLC :lol:

A picture for you guys!



Shouldn't the cylinders be silver for 1970?
That being said, I can't find anything wrong with it... Apart from the fact that it was imported from the US!
No way to know how many miles it's done, since the kmh speedo is not original.
Your impressions?

Rivera, I do understand a BMW is more... user friendly!
I'm looking for a bike that will work, if cared for.
I'd be more than happy to improve the bike step by step and take care of every weak spot, but I want the bike to ride.
Is it too much to ask from a Norton?

cappo said:

Shouldn't the cylinders be silver for 1970?

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Probably.

cappo said:

That being said, I can't find anything wrong with it... Apart from the fact that it was imported from the US!

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The seat or the seat cover is wrong for the year, also the headlamp brackets and fork gaiters are wrong for a '70 Roadster and the headlamp shell should be chromed not black, the rear light cover probably should be silver, also, as far as I'm aware, Roadsters in black (with gold 'D' tank stripe) were not available before 1971.
This bike also has a single Mikuni carb!

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

According to Joe Seifert's records mine was delivered as a black Roadster in May 1970 to Gus Kuhn.
Framenumber 1371xx.
Underneath the black paint I found the Royalblue Fireflake gel coat in the sidepanels and tank.

You guys are just awesome, I'd be lost without your help (and just buy some crippled bike)

As it looks like I can't find a proper 750 example right now. I'll keep looking... As I said, no pressure

Does this Mikuni conversion really make so much sense? Are the Amals that troublesome?

I'll just show you some pictures of the 850 MK1 I could have a look at today.

cappo said:

Does this Mikuni conversion really make so much sense? Are the Amals that troublesome?

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Twin Amals can become more temperamental and difficult to keep synchronised once they are worn, (which most original Amals are likely to be by now) so in that respect, the Mikuni is a sensible option although there is usually some loss of performance with the single carb but this may not be important to you. New Amals aren't that expensive.

cappo said:

I'll just show you some pictures of the 850 MK1 I could have a look at today.

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That certainly is a more factory spec. example, except for the seat cover and handlebar grips! Edit: Oh, and the direction indicators are missing.

There is one in the big kanton way up north:
https://www.ebay-kleinanzeigen.de/s-anz ... 4-305-9481

or this one:
https://www.ebay-kleinanzeigen.de/s-anz ... 7-305-5412

Thanks for looking out for me!
Rivera, that '75 looks pristine! I'm not sure I'm looking for a MKIII, the price is quite high as well...
I read a lot about the MKI and MKII being the loved ones, and the MKIII the heavy cruiser ones!
Is there much difference between the different MKs?
The '71's project, I'd love to restore a Commando... Unfortunately I don't have enough time on my hands to push such a thing through!

L.A.B., I'll have a look at this '73 and report back.
Anything I should carefully examine?

cappo said:

I read a lot about the MKI and MKII being the loved ones, and the MKIII the heavy cruiser ones!
Is there much difference between the different MKs?

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The Mk3s are heavier, but they have several refinements over the earlier models so can be a matter of preference.

cappo said:

I'll have a look at this '73 and report back.
Anything I should carefully examine?

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Apart from the 'usual' checks (brakes, tyres, steering, forks, dampers, wheel bearings, loose spokes, drive chain, etc. etc.)
Does it...
Have good compression?
Start easily hot or cold (the starting technique can take a while to master if you are not used to kickstarting such a large capacity machine, but the owner should at least be able to start it reliably)?
Are there any significant engine knocks rattles?
Does it smoke (some smoke is acceptable when cold).
Does it idle steadily when warm?
Gears all select?

Any oil leaks, best checked after the engine has been running?
Take hold of the rear tyre with one hand and with the other hand on the frame push and pull the rear wheel from side to side to check for excessive movement or play.