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Lucas K2FC Magneto questions #424479
03/16/12 12:28 pm
03/16/12 12:28 pm
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Posts: 329
Concord Township, Ohio
57nortonmodel77 Offline OP
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Concord Township, Ohio
Hi all,
I will need to find a K2FC Lucas mag for my '60 Norton Nomad, part number 42350H. I realize it is a competition model by the "C". I am trying to find out what I should be looking for on buying this specific mag. Do I need to find one with the exact number 42350H on it? Am I OK to find any K2FC mag & when its rebuilt, have it done as a 42350H? Is there a chart, or website that tells me what the differences are on the 42350H versus other K2FC models?
Thanks,
Skip


Magneto & Dynamo restorations & supplies

My Bikes
1948 Norton 500T Trials bike
1950 Norton Model 7
1952 Norton ES2
1957 Norton Model 77
1960 Norton Nomad 600cc Desert sled
1961 Norton ES2 (slimline)
1964 Norton Atlas Scrambler
1972 Bultaco Alpina
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Re: Lucas K2FC Magneto questions [Re: 57nortonmodel77] #424686
03/17/12 4:51 pm
03/17/12 4:51 pm
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Mattsta Offline
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Hi.

The K2FC magneto differs externally from the standard magneto in that the pick-up holders are fixed to the magneto body with 2 screws. They often have a red badge saying "Lucas Competition" on them.

Finding an original and genuine competition magneto will cost you A LOT of money. You can cheat by getting yourself a standard K2F magneto and have the magneto body drilled and tapped for the competition pick-up holders. You can also badge it as a competition mag easily.

There's a guy who posts on these forums called "Magnetoman" and he is pretty knowledgeable about Lucas magnetos.

He will also be able to tell you if there are any internal differences in the K2FC magnetos.

Actually, I had my magneto converted to competition spec with the pick-up holders secured with screws only to discover that the front one fouled on the drive side crankcase of my engine.
So after all that, I ended up using the standard ones.

Is the Norton Nomad fitted with a competition mag as standard? If not, I'd would advise you to check that you wont end up with the same problem I had!

Just found this thread on the Jockey Journal forum. This might help you.

http://www.jockeyjournal.com/forum/showthread.php?t=62503

Last edited by Mattsta; 03/17/12 4:58 pm.

1952 Triumph T100 in a BSA A7 Frame
Re: Lucas K2FC Magneto questions [Re: 57nortonmodel77] #424749
03/17/12 9:21 pm
03/17/12 9:21 pm
Joined: Aug 2001
Posts: 2,122
Oztralia
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Rohan Offline
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Unless you are actually going to race it, or ride it through swamps and rivers, the standard K2F will work perfectly well for road use ? Could be borrowed from another of your Nortons - while you hunt the elusive golden fleece.

If its to be a 100% concours example, doesn't the 42350H just tell you what bits were fitted internally/externally to the K2FC - looking at another Nomad should show what is required ? Triumph maggies for example have gear drive, so have a different shaft to suit ? Cheers.

Re: Lucas K2FC Magneto questions [Re: Rohan] #424766
03/17/12 11:16 pm
03/17/12 11:16 pm
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Magnetoman Online content

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Originally Posted By: Rohan
doesn't the 42350H just tell you what bits were fitted internally/externally to the K2FC -
I only happened to notice this response. The identical question was posted on the 'British Motorcycles in General' forum, and I responded to it there. It would be nice if people avoided posting the same question in more than one location. Or, if they realized they should have posted it elsewhere, if they went back and made a note pointing out they were moving the discussion to the new location.

Re: Lucas K2FC Magneto questions [Re: 57nortonmodel77] #424796
03/18/12 1:56 am
03/18/12 1:56 am
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Oztralia
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Rohan Offline
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Oztralia
Its common to see the same question posted all over the place - presumeably to get a variety of answers most suited to the askee's inclinations ?

BigD Cycles' resto of their Nomad looks to be just using a standard K2F ? Would also give an auto advance, more suited to road/display use ?

http://bigdcycle.com/blog/wp-content/uploads/2009/07/DSCF1781-1024x768.jpg

Re: Lucas K2FC Magneto questions [Re: Mattsta] #424805
03/18/12 2:31 am
03/18/12 2:31 am
Joined: Jan 2008
Posts: 329
Concord Township, Ohio
57nortonmodel77 Offline OP
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Thanks! The K2FC was standard on the Nomad, as I understand it the K2FC was available with manual or auto advance, mine is supposed to have the manual advance, but I am debating on the auto as it would be a lot more user friendly.
Skip


Magneto & Dynamo restorations & supplies

My Bikes
1948 Norton 500T Trials bike
1950 Norton Model 7
1952 Norton ES2
1957 Norton Model 77
1960 Norton Nomad 600cc Desert sled
1961 Norton ES2 (slimline)
1964 Norton Atlas Scrambler
1972 Bultaco Alpina
Re: Lucas K2FC Magneto questions [Re: Magnetoman] #424807
03/18/12 2:35 am
03/18/12 2:35 am
Joined: Jan 2008
Posts: 329
Concord Township, Ohio
57nortonmodel77 Offline OP
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Concord Township, Ohio
Thanks magnetoman, I placed my question in 3 places, Norton, competetition, british m/c in general. I thought it applied to all three sections, & wasn't sure which place was best? Should I not do that? Or should I note in my message, also posted in xxxxxxxx & yyyyyyy ? I wasn't sure?

Skip


Magneto & Dynamo restorations & supplies

My Bikes
1948 Norton 500T Trials bike
1950 Norton Model 7
1952 Norton ES2
1957 Norton Model 77
1960 Norton Nomad 600cc Desert sled
1961 Norton ES2 (slimline)
1964 Norton Atlas Scrambler
1972 Bultaco Alpina
Re: Lucas K2FC Magneto questions [Re: 57nortonmodel77] #424811
03/18/12 2:51 am
03/18/12 2:51 am
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Rohan Offline
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Doesn't the C in K2FC mean it has manual advance ??

Re: Lucas K2FC Magneto questions [Re: Magnetoman] #424815
03/18/12 4:36 am
03/18/12 4:36 am
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Pretty much irrelevant post. This isn't a common question and making it available for all to see since these mags were used on more than just Nortons can only help to get him an answer in a timely manner.

beerchug


Originally Posted By: Magnetoman
The identical question was posted on the 'British Motorcycles in General' forum, and I responded to it there. It would be nice if people avoided posting the same question in more than one location. Or, if they realized they should have posted it elsewhere, if they went back and made a note pointing out they were moving the discussion to the new location.


Jon W.


1957 6T Thunderbird 650
1968 T100R Daytona 500
1971 TR6R Tiger 650
1970 BSA A65F 650
1955 Tiger 100 - Project

Re: Lucas K2FC Magneto questions [Re: 57nortonmodel77] #424817
03/18/12 5:13 am
03/18/12 5:13 am
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Magnetoman Online content

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Originally Posted By: 57nortonmodel77
I placed my question in 3 places, Norton, competetition, british m/c in general. I thought it applied to all three sections, & wasn't sure which place was best?

The problem with placing a question in more than one location is information that may not be correct can get posted in some of the responses and not be corrected by subsequent ones, because parallel discussions are taking place in other forums that are not necessarily aware of each other. Having everything in one place usually either leads to converging on concensus conclusion, or to conflicting answers where it's clear what the choices are. Your question was about a K2FC, not about something Norton-specific, so it seems to me the 'General' forum is the perfect place for it.

Re: Lucas K2FC Magneto questions [Re: Magnetoman] #424839
03/18/12 10:09 am
03/18/12 10:09 am
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triton thrasher Offline
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Originally Posted By: Magnetoman
Originally Posted By: Rohan
doesn't the 42350H just tell you what bits were fitted internally/externally to the K2FC -
I only happened to notice this response. The identical question was posted on the 'British Motorcycles in General' forum, and I responded to it there. It would be nice if people avoided posting the same question in more than one location. Or, if they realized they should have posted it elsewhere, if they went back and made a note pointing out they were moving the discussion to the new location.


New guys don't realise it's better to ask once. I'd have asked it in the Norton forum and maybe put a pointer to the query, in British Bikes in General. Or the other way round!

Last edited by triton thrasher; 03/18/12 10:11 am.

Amateur Loctite enthusiast.
Re: Lucas K2FC Magneto questions [Re: 57nortonmodel77] #424862
03/18/12 12:31 pm
03/18/12 12:31 pm
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Hamilton, Mass. USA
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Dave Comeau Offline

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K2FC is manual OR AA...I have both. I'd prefer the AA even on a cable advance unit.

Rohan the mag shafts do not differ....that is probably the dynamo your thinking of which can be tapered ot straight shaft..I have both


dynodave
BSA 3 1961-1963
Ducati 3 1992-2002
Norton many 1951-1975
87 Serv-Equip 100HP MC brake dynamometer,
Re: Lucas K2FC Magneto questions [Re: 57nortonmodel77] #424865
03/18/12 12:42 pm
03/18/12 12:42 pm
Joined: Jan 2008
Posts: 329
Concord Township, Ohio
57nortonmodel77 Offline OP
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Oh, I see now. I wasn't sure I would get the traffic on the general British section. I normally never go there myself, only the Norton specific section (that's just me) as the Nomad was a competition model I thought maybe the comp. section.
I think in the future, on a question like this, where multiple locations would apply, I guess post the question in pone place only & perhaps just a note in other sections to see the orig. location for reply's??????

So, to the original problem...................................

as I understand it the K2FC were avail. in both manual & auto advance?

K2FC had screws rather than clips on the pickups?

K2FC have a vented end cap?

K2FC were available in CW & CCW rotation (as viewed from the drive end)?

Given that, if I wanted an original mag for my 1960 Norton Nomad,
I could use any Lucas K2FC with a manual advance, that turns the correct direction?

No to get tricky............................
Can I use an auto advance to make life easier, but use the casting with the cable entry & run a "dummy" advance cable for appearance?

I have always been one to send my mags out for a total rebuild when starting a project, 40 plus year old electrics are a bad idea. I have always felt a professional with the correct tooling can do the job better than me, since I have never rebuilt a mag & have no way to re-magnetise parts, nor do I have a way to gage the magnetism. On the other hand, I consider myself to be very mechanical, I own a remodeling/maintenance company, I have rebuilt from the ground up a dozen or so cars & twice as many motorcycles of various brands & years & am wondering, how difficult can rebuilding a mag be? I am asking , because I dont know?

Thanks everyone for the responses, I really do appreciate it.


Magneto & Dynamo restorations & supplies

My Bikes
1948 Norton 500T Trials bike
1950 Norton Model 7
1952 Norton ES2
1957 Norton Model 77
1960 Norton Nomad 600cc Desert sled
1961 Norton ES2 (slimline)
1964 Norton Atlas Scrambler
1972 Bultaco Alpina
Re: Lucas K2FC Magneto questions [Re: 57nortonmodel77] #424878
03/18/12 2:12 pm
03/18/12 2:12 pm
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Hamilton, Mass. USA
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Dave Comeau Offline

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K2FC has a end vent fitting that can go to a hose I guess to allow venting up at the steering neck?
The regular K2f is vented with a drilled hole on the bottom for water egress.
You can mount a AA on a cable mag but you must still fix/support the spring loaded cam ring linkage with a cable or other fabricated device.
A very high percentage of mags are CCW.

A new capacitor is absolutely necessary, I'm not as universally sold that a rewind is necessary unless testing indicates the need. I have only ever tested 2 as a bad HV coil. All the rest are still in service.

Last edited by Dave Comeau; 03/18/12 2:13 pm.

dynodave
BSA 3 1961-1963
Ducati 3 1992-2002
Norton many 1951-1975
87 Serv-Equip 100HP MC brake dynamometer,
Re: Lucas K2FC Magneto questions [Re: 57nortonmodel77] #424909
03/18/12 4:24 pm
03/18/12 4:24 pm
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Magnetoman Online content

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Originally Posted By: 57nortonmodel77
am wondering, how difficult can rebuilding a mag be? I am asking , because I dont know?
Mechanically, there's nothing more difficult about rebuilding a mag than there is about, say, assembling a valve train with all the proper clearances. If you're comfortable with electricity, it's no more difficult than, say, repairing a toaster oven whose heating element has become disconnected. However, it does take a few special tools (all of which can be purchased or fabricated), and the right condenser.

The condenser has been the downfall of many a rebuild over the years, by professionals as well as amateurs, because much, much misinformation exists about what properties they need to have in order for them to survive the high current pulses generated by a magneto. A physicist conducted a years'-long study of possible replacement condensers, subjecting them to a rigorous set of tests, and publishing the results in 2011 in a two-part series in the Antique Motorcycle Club of America's magazine. Unfortunately, the Panasonic condensers he recommends are no longer produced, and the stock of them sold out as soon as the magazine appeared. Luckily, I have a lifetime supply, so I'm all set, but currently this is a problem for others. I won't say anything bad about any of the various condensers touted by one person or another, but only repeat that much, much misinformation exists.

Another problem is magnetizing the magneto. Removing the armature from a good magneto causes its alnico magnet to immediately lose ~15% of its strength, resulting in the energy in the spark dropping by over 25% (for pre-WWII bikes that use magnets other than alnico, the demagetizing field is much greater, and they lose quite a bit more). Not everyone who rebuilds magnetos has the very large electromagnet that is needed to restore the field once the rebuilt armature is returned to the body, but since bikes will still run with a 25% reduction in spark energy (although they are harder to start, and miss when the mixtures are too far off), many magnetos are returned to the customers operating only 75% as well as they could. The field strength required to remagnetize a magneto is described in a Lucas technical bulletin. Several years ago I fabricated my own electromagnet that I designed to give 20% higher field than called for, just to be sure. I have no way to weigh it, but it's easily well over 200 lbs.

Yet another problem is the coil. Dave Comeau posted a comment that he has found most original coils to be good, and don't need to be rewound. I agree. I do have the appropriate testers to ensure the coils are good before reusing them. But, if a coil is not good, a replacement needs to be located. This is the one place where I still have to rely on outsiders, since I've yet to break down and start winding my own replacements. I could do it if forced to, but its such a fiddly job that instead I've adopted the 'trust, but verify' approach. The few times it has been needed, I've had someone else rewind the coils, but I then subjected them to extensive high voltage pulse tests at somewhat elevated temperatures to make sure the insulation they've used between the layers of windings won't break down in service.

Although life would be simpler if one could simply pay money to a self-described magneto rebuilder and have a properly refurbished magneto returned to them, life doesn't always work that way. So, either you have to find a rebuilder who really does know what they're doing, or do it yourself. Unfortunately, glowing recommendations are to be found for people who I know are not properly equipped to do a proper job (other than making the outside of the mag look pretty), as well as for people who are equipped. So, separating the good rebuilders from the bad is a quest in itself.

I'll end this by saying I have no personal experience whatever with magneto restorers who post on BritBike Forum, so nothing I've written should be taken one way or other as being about them. I restore my own magnetos myself, and am happy to offer advice to anyone interested in magnetos, but my lack of personal experience with magneto restorers means I am not in a position to make recommendations about any of them.

Re: Lucas K2FC Magneto questions [Re: Magnetoman] #424928
03/18/12 6:26 pm
03/18/12 6:26 pm
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Magnetoman Online content

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Originally Posted By: Magnetoman
I have no way to weigh it, but it's easily well over 200 lbs.
I've long meant to calculate the weight of my magneto remagnetizer from the volume of metal in it, plus estimating the weight of the frame and current supply, but never got around to it. I finally did it a few minutes ago. It weighs ~250 lbs., and the iron and copper alone would cost ~$500 at the value google shows they're trading for today. This is what is needed to restore the magnet in a magneto to the full value it left the factory with.

Re: Lucas K2FC Magneto questions [Re: Magnetoman] #424931
03/18/12 6:37 pm
03/18/12 6:37 pm
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Posts: 329
Concord Township, Ohio
57nortonmodel77 Offline OP
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Thanks again for the info, I had been sending my mags to Hawker electric & he did a great job, but he no longer rebuild them, as his parts selling side of his business is taking away all his time & I am sure created a better profit margin.

I have read some talk about degradation of the shellack on coil winding on old mags, I assume by your comments that is really not an issue? Or , if it has continuity when "warm" it should be OK?
when testing the winding's at operating temperature, what temp. do you test at?

Do you have the model number/specs on the Panasonic capacitor? I have some friends in that line of engineering that may be able to help.

Thanks,
Skip


Magneto & Dynamo restorations & supplies

My Bikes
1948 Norton 500T Trials bike
1950 Norton Model 7
1952 Norton ES2
1957 Norton Model 77
1960 Norton Nomad 600cc Desert sled
1961 Norton ES2 (slimline)
1964 Norton Atlas Scrambler
1972 Bultaco Alpina
Re: Lucas K2FC Magneto questions [Re: 57nortonmodel77] #424950
03/18/12 7:20 pm
03/18/12 7:20 pm
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Hamilton, Mass. USA
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Dave Comeau Offline

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shellac on old mags....pretty much pre war according to guys that work on stuff that old. Our norton twins don't qualify.

I read that article on mag condensers/caps and was interested to find "some" people do know something about the field I work in every day...
I was not able to find the dv/dt value of the panasonic cap (which is one of the critical values)... though 400-600v .19-.22uF are some of the other values.

mag man
what kind of voltage and current you run in your gausser. I'm running about 1500v and several hundred amps through an ignitron dicharge of a killer cap bank through the coil. laugh

I seem to max out or saturate the magnets in the mag body when I pulse my gausser several times. Then I get no more improvement. I test my mag body magnets with a RFL gaussmeter positioned by an aluminum machined probe fixture.
I seem to be able to boost mine by 15-20% unless they are REAL bad to begin with then the improvement is huge.

Last edited by Dave Comeau; 03/18/12 7:20 pm.

dynodave
BSA 3 1961-1963
Ducati 3 1992-2002
Norton many 1951-1975
87 Serv-Equip 100HP MC brake dynamometer,
Re: Lucas K2FC Magneto questions [Re: Dave Comeau] #424965
03/18/12 8:45 pm
03/18/12 8:45 pm
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Magnetoman Online content

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Originally Posted By: Dave Comeau
shellac on old mags....pretty much pre war according to guys that work on stuff that old. Our norton twins don't qualify.

I was not able to find the dv/dt value of the panasonic cap (which is one of the critical values)... though 400-600v .19-.22uF are some of the other values.

what kind of voltage and current you run in your gausser. I'm running about 1500v and several hundred amps through an ignitron dicharge of a killer cap bank through the coil. laugh

I seem to max out or saturate the magnets in the mag body when I pulse my gausser several times. Then I get no more improvement. I test my mag body magnets with a RFL gaussmeter positioned by an aluminum machined probe fixture.
I seem to be able to boost mine by 15-20% unless they are REAL bad to begin with then the improvement is huge.

As you say, it's the pre-war magnetos where the shellac allegedly can run when it gets hot. I say "allegedly" because none of those early magnetos I've had apart has shown any sign of melting. That doesn't mean it can't happen, but this could be just another example of something repeated enough times by magazine writers copying what each other has written that it has become accepted as true.

The Panasonic capacitors are 0.082 uF, part no. ECQ-P4823JU, and need to be soldered in parallel to created the necessary 0.16 uF. Their dV/dt is 6000 V/us.

There are two approaches to making an electromagnet: relatively high resistance coils with a high voltage to achieve the necessary current (I=V/R), which is the approach you took. Or, lower resistance coils with a lower voltage. I went the latter route. Although it might be possible to design a suitable electromagnet that worked with the current from a 12V car battery, I rectified the 240V single-phase current in my garage to create ~240 VDC. I first run the AC through a very large Variac before sending it to the rectifier, so I can vary the voltage (and current) anywhere from 0 up to the maximum that can be delivered into the resistance of the coils. Lucas calls for 65,000-70,000 A-turns, and mine gives me ~80,000 A-turns at ~17 Amps (current measured with a clamp-on meter, voltage measured with another meter, as is resistance -- the measured I indeed equals the measured V divided by R, as Mr. Ohm told us it must).

However, the outer turns of any magnet aren't as effective at saturating the iron core as are the ones immediately adjacent to it, so all A-turns aren't equal. To keep my magnet honest, I have two Bell gaussmeters; an older analog one as well as a smaller, more convienient digital version. The gaussmeters show that my magnet is driven into saturation by 15 Amps, so the extra capacity I gave it is a bonus that could be helpful if a particular magneto has a design that keeps me from getting the pole faces as close to it as I would like. I made flat, convex, and concave pole faces that have dealt with every Lucas, BTH, Bosch, Fairbanks-Morse,... magneto or magdyno I've come across so far, plus extra pieces of iron to make custom faces if that need ever arises in the future.

I sacrificed an old armature to make a fixture that allowed me to have a magnetometer probe inside a small air gap in a magneto while magnetizing it. Here, having two magnetometers was useful, allowing me to watch what was going on with the fields inside and outside the magneto at the same time. Since I use a Variac, I run my current up slowly compared to your discharge (I might take 5 sec., but yours still is limited by the L/R of your coil), and found from this test that one cycle is all that is needed to fully remagnetize the magnet. Still, even though my measurements show it doesn't increase anything, it's easy enough to run the field up a second time, so I always do.

Some magazine articles advise the reader to insert a large socket in the magneto immediately after removing the armature to act as a "keeper" to retain the full magnetism. Sadly, this advice doesn't work. The magnetic domains rearrange themselves nearly instantaneously, so the cows are long gone by the time you close this barn door.

Re: Lucas K2FC Magneto questions [Re: 57nortonmodel77] #424971
03/18/12 9:00 pm
03/18/12 9:00 pm
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Magnetoman Online content

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Originally Posted By: 57nortonmodel77
Or , if it has continuity when "warm" it should be OK?
when testing the winding's at operating temperature, what temp. do you test at?
Oops, I forgot to answer this question. Almost always, if there's a failure of a magneto when it is warm, it's due to the condenser. However, when there is a failure of the coil at elevated temperature, the problem usually isn't that the wires have separated (i.e. become discontinuous), but that the insulation between layers of the coil allow arcing to take place. A DC measurement of continuity won't reveal this problem if it exists. I put coils in a toaster oven at 140oF and run wires to one of my testers. It is very unlikely the inside of a magneto ever will reach this temperature, but if it passes this test, it means never having to worry about it failing due to heat exhaustion.

Re: Lucas K2FC Magneto questions [Re: 57nortonmodel77] #424981
03/18/12 9:28 pm
03/18/12 9:28 pm
Joined: Jan 2008
Posts: 329
Concord Township, Ohio
57nortonmodel77 Offline OP
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57nortonmodel77  Offline OP
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Joined: Jan 2008
Posts: 329
Concord Township, Ohio
I see, so the heat test is basically testing the capacitor right? I auctually have 2 magneto issues,

1) find a K2FC for my Nomad
2) test the K2f on my '50 model 7.

The model 7 mag puts out a fat blue spark when turned by hand, but I feel the bearings are too loose to install the mag, so I may do the heat test for the cap. & put in 2 new bearings, and I asssume new carbon brushes? The model 7 is not getting a full rest, I am going to leave the patina on it & ride as is. It was a basket case motor so new bearings,chains, etc. in the engine, new brake,cables, bearings everywhere else.
The Nomad on the other hand will be a nut & bolt museum quality resto.
Thanks again for all the info!
Skip


Magneto & Dynamo restorations & supplies

My Bikes
1948 Norton 500T Trials bike
1950 Norton Model 7
1952 Norton ES2
1957 Norton Model 77
1960 Norton Nomad 600cc Desert sled
1961 Norton ES2 (slimline)
1964 Norton Atlas Scrambler
1972 Bultaco Alpina
Re: Lucas K2FC Magneto questions [Re: 57nortonmodel77] #424996
03/18/12 10:45 pm
03/18/12 10:45 pm
Joined: Nov 2011
Posts: 4,488
U.S.
Magnetoman Online content

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Magnetoman  Online Content

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U.S.
Originally Posted By: 57nortonmodel77
The model 7 mag puts out a fat blue spark when turned by hand, but I feel the bearings are too loose to install the mag, so I may do the heat test for the cap. & put in 2 new bearings, and I asssume new carbon brushes?
Magneto bearings are of the cup-and-cone variety, so loose bearings almost always are easily rectified by a thinner shim between the main housing and the points housing. However, the excess clearance could be caused by disintegration of the paper insulator(s) between one or both of the races and the housings. That's also easily fixed, but requires disassembly.

If the condenser is the original one, it likely is either already bad, or soon will be bad. Getting a spark when turning it by hand doesn't really test the condenser. Even a bad one will still allow a spark to be generated.

Carbon brushes only wear out, they don't go bad. If they're long enough, just continue to use them. Replacing them with aftermarket ones brings up yet another possible problem. If the replacement carbon is too hard, it will quickly wear a groove in your slip ring. If it's too soft, it will leave a trail of carbon dust that can become the source of another short to earth.

Re: Lucas K2FC Magneto questions [Re: 57nortonmodel77] #425002
03/18/12 11:12 pm
03/18/12 11:12 pm
Joined: Aug 2001
Posts: 1,269
Hamilton, Mass. USA
D
Dave Comeau Offline

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Dave Comeau  Offline

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D
Joined: Aug 2001
Posts: 1,269
Hamilton, Mass. USA
mag man
thanks for the reply.
Skip
Unfortunately I would shy away from the real early mags. They have a small drive end bearing and therefore a small shaft that can be "tender". One of my older samples has a broken off drive end. A beefier atlas one would work fine.

Comment on mag caps. I have a 0-1000vps with uA meter. one of the first tests I do is test the cap to 400v...I have yet to find the first GOOD original cap, even on a rather late (IIRC) 1972mfg service K2f mag. yet virtually all will spark but not necessarily run an engine.


dynodave
BSA 3 1961-1963
Ducati 3 1992-2002
Norton many 1951-1975
87 Serv-Equip 100HP MC brake dynamometer,
Re: Lucas K2FC Magneto questions [Re: Dave Comeau] #425005
03/18/12 11:49 pm
03/18/12 11:49 pm
Joined: Nov 2011
Posts: 4,488
U.S.
Magnetoman Online content

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Magnetoman  Online Content

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Joined: Nov 2011
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U.S.
Originally Posted By: Dave Comeau
one of the first tests I do is test the cap to 400v...I have yet to find the first GOOD original cap, even on a rather late (IIRC) 1972mfg service K2f mag. yet virtually all will spark but not necessarily run an engine.
I think it's funny to see how much a "rare, original, NOS Lucas magneto condenser" sometimes sells for on eBay. That AMCA article last fall explained at a pretty fundamental level why all Lucas condensers are either already dead, or are on life support.

I, too, test all the old condensers, but just out of curiousity. Even if I found one that passed the tests (which I never have), there's no way I would use it. Even if still functional today, its days would be numbered.

Re: Lucas K2FC Magneto questions [Re: Dave Comeau] #426269
03/25/12 9:24 pm
03/25/12 9:24 pm
Joined: Sep 2007
Posts: 1,113
Ottawa, Canada
gREgg-K Offline

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gREgg-K  Offline

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Posts: 1,113
Ottawa, Canada
Originally Posted By: Dave Comeau
<SNIP>Skip
Unfortunately I would shy away from the real early mags. They have a small drive end bearing and therefore a small shaft that can be "tender". One of my older samples has a broken off drive end. A beefier atlas one would work fine.<SNIP>


Agreed Dave, the earlier K2Fs having the E15 drive end bearing tend to be fragile, with the armature stub being prone to parting ways with the brass bobbin caps. However, I have had several examples of the later K2F with the larger E18 bearing suffer the same fate ... one as recently as December 2011.

This damage I have attributed to the brutal practice of people using a hammer "shock" the drive pinion off its taper, rather than using a proper puller.

... Gregg


Spyder Integrated Technologies
Lucas, BTH, & Miller Magneto & Dynamo Restoration
SMITHS Chronometric Restoration
magneto@spyder-it.com
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