Norton N15CS Hybrid restoration

Nortons have the most notorious kick ratio of about any bike ever sold. The raise of CR to 10 in Combat had about nothing to do with the Norton folly, just made those errors show up sooner. There are more Combats made and still going than any other model, after the folly is removed and CR retained. You might consider joining the UK original Norton Owners Club as they have folks familiar with the pre-Commando variations, but no long a public forum list.
 
hobot said:
There are more Combats made and still going than any other model

The first Combat-tuned Commando was supposedly 200976, and the last was supposed to have been 211110 which amounts to 10135 Commandos assuming there were no gaps in the serial numbers but, not all of those were built as Combat-engined models.
850 Mk3 production started at 325001 and continued on to 336539 (or 336538 for some!) which is a total of 11539 (or 11538) 850 Mk3 Commandos, again, that's assuming there were no gaps in the Mk3 serial numbers, so there were probably more 850 Mk3s built than 750 Combats!
 
Okay, got the primary re-assembled and did a basic compression test. This is cold, with basically dry cylinders, pistons & rings, just the residue from the assembly oil.

Also, it's with one hand holding the guage while kicking, resulting in less than stellar efficacy of the procedure, as it's hard enough just getting a thump and a half out of it with both hands on the bars!

Just under 100 on the left side, just over 100 on the right. I think I need to get a helper to hold the guage and give it some more concentrated kicks to get reliable readings.

Basically inconclusive, but I don't think too much compression is an issue.

Norton N15CS Hybrid restoration


Norton N15CS Hybrid restoration
 
I guess it's better to do this so you are sure in your own mind that everything is OK. If something isn't right, starting it on the rollers in the hope that it loosens up could do damage.
 
daveh said:
I guess it's better to do this so you are sure in your own mind that everything is OK. If something isn't right, starting it on the rollers in the hope that it loosens up could do damage.

YAHTZEE!

On one of MY bikes, MAYBE.
On CLIENT'S bike? NEVER!
 
"This is sewious" (in the voice of Wonder pets 'Ming-Ming', you have to have a small kid or grandkid to understand).

I need to get this done with temps over 100 every day, and my shop A/C not cutting it without setting up area cutains to keep the heat out of the small space that it can handle, so it's back in my office we go-

Norton N15CS Hybrid restoration


Let's face it, Commando primaries are easier to remove, less "stuff" to deal with-

Norton N15CS Hybrid restoration


Also having 4-part engine mounts with 9 bolts, and at least one of the two rear tranny mount bolts having to come out to tip the engine makes it that much more fun. I use a strap to lift the engine as it pivots on the single rear tranny mount, then pull out the last engine mount bole that there's no way to get to between the lower frame rails-

Norton N15CS Hybrid restoration


Hmmmmmm... Deja Vu...

Anyway, I'd have like to have a helper, but it's out with no scratching of the frame (I'm getting too much practice on just one bike)-

Norton N15CS Hybrid restoration


I earned a steak for lunch.
 
I have a 1966 Norton Atlas 750 in a Matchless Scrambler frame.
It looks to be the same as the N15CS Hybrid restoration pictured in this article.
How can I determine the difference between the N15 and the G15?
This thread is dated, but so am I.
A local machine shop rendered my cylinder head unusable, so I am looking for an Atlas 750 cylinder head, and a source for new pistons and rings.
My Norton has not run for 30 years, but I really should make it run again one day.
There was really nothing like the "Snortin' Norton".
 
Isn't the difference in the numbers ?
Nortons used something in the Norton sequence of numbers, and Matchless used the Matchless sequence. Does the engine say G15 etc ?
 
I will gather the numbers off the motor when I get over to where it is stored.
My Title Vin Number is 114129, but it only says 66 Norton Atlas.
 
In that case we need a pic of it too, since anything can have happened in the past 45 years.
Sounding more Norton than Matchless at this stage though, the engine at least.
Probably need a new thread too, so as not to hijack GP's rebuild here.
 
I can't help wondering how this resto project's been going since July, when grandpaul last posted about it. My once upon a time sole means of transport and 1990s daily driver N15CS is patiently sitting in its shed awaiting its resurrection and long overdue rebuild (Hell, it sorely needed a rebuild when I got it, partly in crates, for $100 from a guy in Hearne, Texas whose late uncle had apparently never registered it, but just used it on the ranch). After just lurking hereabouts for some time, marking the resto's progress, I finally have to confess that this thread's been something of an inspiration to finally get my own clapped out "rat bike" a little better squared away at last, so I hate to see the whole thing just left sort of dangling, with the engine on the floor...

Best to all!
Bilgey
Woodbridge, Virginia
 
GARY72 said:
I have a 1966 Norton Atlas 750 in a Matchless Scrambler frame.
It A local machine shop rendered my cylinder head unusable, so I am looking for an Atlas 750 cylinder head, and a source for new pistons and rings.
There was really nothing like the "Snortin' Norton".

Depends where you went for the opinion on the head, you will be surprised what can be done to restore a cylinder head these days.
 
Hi, I have read this article with interest. I live in the UK, and bought one of these new in 1969 from Gus Kuhn in London. I used to belong to the National Sprint Association, and did a standing quartet in 13.6 seconds at Duxford Aerodrome in 1970. According to an aquaintance of mine who worked for Norton, and built some of the last of these in 1969, the factory used up any parts to hand that fitted. He said that mine had a commando engine as they had run out of Atlas parts by then. The vibration was bad untill it had done 12000 miles. It needed 100 octane petrol too. It used to shear silencer bolts, etc. I loved the bike, but sold it to finance my first house when I got married. It still exists somewhere. The reg. No. was WYM409H. Best regards on a fine restoration, Paul
 
This project has been eating my lunch. Everything shapes up nicely 'till I get it all back together then it just refuses to fire.

I'm on the third teardown (twice to the primary, once all the way back down to re-check the rod bolts & big end shells; one of those times it got the thick base plate, this last time it's getting the cam drive timing checked)

It's a real bugger because of the primary cover with the captive alternator stator requires considerable loosening of hardware to wiggle the sucker free without scuffing the polished aluminum, and the entire fiddle with the AAU magneto. I've nailed the mag timing with the degree wheel, double & triple checked and it just won't fire. This last time around, I've lost spark from the freshly overhauled K2F.

Since the owner took over a year to decide what he wanted, and another 6 months to give me the go-ahead and deposit, I'm thankful he isn't in a hurry or panic to see it done. One thing for sure, it'll be done RIGHT.

Let he who is without sin cast the first stone...
 
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