My new Norton Atlas

Old and tired maggies have the odd behaviour that they can spark well when cold, but the spark fades when hot - when they can be almost impossible to start again if stopped.
Bear this in mind, for reliable motoring, without a magneto rebuild.

Overtightening the manifold studs can warp the carb bodies - do they operate OK once fitted back and the studs correctly tightened down, not too tight.
If the throttle doesn't shut off, the ride can be - exciting....

What does the oil look like that came out of it.
If its old and crusty looking, its a gamble trying to run it like that.
And the oil pump seal, inside the timing cover, is always worth checking that it has not deteriorated - and the oil pressure to the crank lost.

You hear stories of folks riding off happily into the sunset.
After some prelim work getting it shipshape again....

Magnetos are like most British motorcycles - designed to drive us insane. Unless it is a rotating magnet type - forget it, and run an electronic ignition. Many tractors and stationary engines use the Lucas SR type, which can be used on a British bike with slight adaptation. I used a four cylinder one on my triumph twin for many years by putting two leads to each spark plug. The bike revved easily and reliably to 10,500 rpm. Twin cylinder and four cylinder Lucas SR magnetos are the same except the four cylinder one has a geared rotor button, and a different cam, they can be converted. Should be cheap from a machinery dealer, just takes a bit of searching to find one. It will last you forever.
http://www.ebay.co.uk/sch/i.html?_nkw=lucas+sr+magneto

So that gave you a wasted spark on every inlet stroke ?!
Musta been - interesting.

Pay no notice of aco, modern rebuilt magnetos, with epoxy encased wires, a modern hi-volt capacitor, and well sealed, are good for another few decades of reliable motoring.

Electronic ignition requires a reliable electrical system as well, and if anything fails or becomes unplugged or wet, its home on the trailer.

At least with a magneto, it'll keep going no matter what the electrics are doing.
Don't even need any electrics....

'So that gave you a wasted spark on every inlet stroke ?!
Musta been - interesting.
'

No wasted spark, the rotor button runs at half speed on an SR4.
I any case my current 850 motor has a wasted spark on every inlet stroke.
An SR2 is an excellent option for an old British twin. I raced my old 500 triumph for twelve years against another friend who had the same problems that I had - rebuilt magnetos failing immediately after we had paid money to several 'experts'. There is currently only one guy in our state who can rebuild a magneto, and even some of his have been known to fail. I recently gave a Lucas wader racing magneto to a mate of mine, I never want to see one again. If you want a bad day at the races and a waste of money, that is the way to get it.
With an SR2, the coil is replaceable, and the condenser is external. The SR1 which is used on Manx Nortons and G50s has a different rotating magnet set-up, but an industrial SR is easily adequate for most racing, and certainly for road use. The magnet system used in Lucas racing magnetos will fit.

http://www.ebay.co.uk/sch/i.html?_nkw=lucas+sr+magneto

All that needs to be done is to strip off the impulse start crap, and make an adaptor plate and platform. The SR2 in the ad is priced at $15, can you even buy a set of points for a lucas wader for that ?

Indeed, many multi-cylinder Nippon machines use dual output/wasted spark coils, inc my RZ 350 Yamaha 2-strokes..
I recall, that as a schoolboy prank, Matt Spencer swapped the hi-tension/plug leads over on a cop Honda 4, & was perplexed when the cop started it & rode away , unaffected..

Wasted spark on a two stroke is not a good thing. If it actually succeeds in firing, it can pop a crankshaft seal. My 850 has fired as I connected the battery, and shot a mate of mine in the leg. Setting up the SR$ was quite confusing. I paired the opposite leads from the distributor cap, but it's a bit mind bending getting it right. For each two crank rotations, there are four firings intended for four cylinders. I redirected every second one to the same cylinder of a twin cylinder motor . Have a think about it, it is good fun. It just means the spark comes up the other lead on every second firing.
(I was too lousy to convert it into an SR2 and I think the SR4 has two sets of points).
http://www.eastyorkshire.co.uk/eddsfiel ... on_man.htm

The only technically annoying issue I`ve experienced with it [RZ] is - if a lead is dis-lodged or water-inundated the whole plot stops firing - due to the juice [electrickery] following the path of least resistance..

We use those British Lectrix ignitions systems on the H1 and H2 Kawasakis, and they are great. The 750 popped a lead out of a coil, and my brother plugged it in again and raced in the next race. The motor detonated and cracked the head on the corresponding cylinder, and so we bought a new system box for that cylinder. It can get expensive, the heads are all reshaped about 300Km away in East Gippsland.

'I recall, that as a schoolboy prank, Matt Spencer swapped the hi-tension/plug leads over on a cop Honda 4, & was perplexed when the cop started it & rode away , unaffected..'

A cop probably wouldn't even notice if his bike lost half of its horses.

Yes, but it did run on all 4, & re 2Ts, not much room for error on those so-quick timing events, it can be a bit of a bugger even getting a strobe/timing light that will cope with hi-rev 2Ts..
Although, I`ve seen the MOPAR [Valiant] electronic box adapted to H1 use, the triple needing the same number of sparks as a 4T six..

acotrel said:

My 850 has fired as I connected the battery, .

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If you watch closely, veteran cars pre about 1913 don't have starter motors. (weren't invented).
Yet many have push button starting.

How is this possible ?
They have a special feature on the magneto, when switched over, that sends a battery-generated spark to the next cylinder - and it starts. Magic to see. All the best (as in expensive) cars had them. None of this crank-handle business, except first thing in the morning to stir things up.

In the Model T, four trembler coils were used, one for each cylinder. This was a precursor of the modern use of individual plug-top coils,

Fearfully Advanced , saves breaking wrist ( or ankle ) . :? :roll: Obviously the best . ! most sold .or was that the V.W. :lol: :mrgreen:

72westie said:

I just picked this up this morning, thanks to a friend who found it on Craigslist for me, and also went and bought it and picked it up for me. It ended up being 2 miles from his house. Its a number's matching '66 650. I think its a model 88, but maybe someone can confirm it for me? Motor is free and has good compression. Light work when I hooked a battery up, but no spark. I checked the mag point out, they are freshly cleaned, gapped to spec and still now spark. Is there any tricks to working on a Magneto? It's my first one.

Click to expand...

This bike would look great chopped or fully restored. Very cool score! Btw nice Westy, I just finished a partial resto on my 85'. Don't know how I ever lived without it.

Chopped ! Chopped ? YOURE NOT ALLOWED TO ' CHOP ' IT . :lol:

Tastefully done coustom however I might take for a spin if pressuered .

"PRESSURED"! sure, but - by Drouin or Nitro [or other chemical] means? ...L.O.L...

I already have one Norton that was chopped when I got it, it's now back to stock. Right now I am just trying on getting it running. Once I get it running and rideable, I may ride it like it is for now. I have a few projects I need to finish first before I get too deep into this one.

The chrome on the wheels is shot, no saving that. Pretty much all the chrome will need redone, it's flaking off. I am hoping that I don't end up with a piece in my hand, that shit hurts!

The left carb body would be useable I think if I could get the jet holder piece and slide back in. It is warped right at the top. The slide was able to fully open and wasn't sticking. It was when I tried to remove the slide that I found the difficult area. I asked a buddy to check if he has a carb body for me.

I also need a correct tail light setup and a tachometer. It currently has a commando tach on it. Anyone want to trade?

I am watching your thread with great interest. I am in the process of bring back TWO Atlas motorcycles. One is a 1966 and the other is a 1967. I am a glutton for punishment I suppose as the process of locating simple items like hardware and the whitworth nuts/bolts is frustrating. At least your's is together and complete. My 1966 has a magneto and the 67 has a distributor and points. There is a learning curve but for me that is half of the fun. Best of luck with it!

My project also came with a small box of parts, mainly the old used valves and some gears, but there is a can of old fasteners too.

Have you thought about the joe hunt magnetos that JSMotorsports sets up for nortons & offers on his website? Rare earth magnets offer up a healthy spark it seems.

At first, I thought it was a 650SS. It looks a lot like the company hack I rode to work for a year or more (except mine had a seat!). If it's really a 750 Atlas and you plan to ride it much, get all your tooth fillings re-glued and buy a stock of headlight bulbs. The vibration that the rigid engine mounts transmit to the rider are tremendous. The headlight bulbs will be shot after 5000 miles whether you have the lights on or not. Th vibration shakes the filament off the posts inside the bulbs. I couldn't ride an Atlas more than about 120 miles without getting numbness in fingers and feet. IMO, the performance you got wasn't worth the discomfort.

I never did figure why the Atlas was so bad compared to the 650SS. I rode the 650 every day back and forth to work, 48 miles each way for 15 months and the vibration wasn't a big deal. A brief time with an Atlas, and I was ready to ride the bus to work! Instead, I finished up riding a scooter, made by Villiers India, called the "Fantabulous". It had an electric start Villiers 9E engine. The other bike I rode was a 50cc Italian 2-stroke called a "MOTOM" which N-V were considering importing. The riding position could best be described as "here's my head, my ass is coming". It had a 4-speed twist grip gearshift, wheels and tires that looked like they should be on a bicycle and it got worse gas mileage than the 650! N-V, in a rare case of good sense, decided not to pursue its importation.