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In this country, the SR got itself a reputation for bad starting on Enfield twins.
650 Norton Vibration and Balance Factor
- Thread starter 650SS
- Start date
acotrel said:
Obviously not - since Enfields made in india have only ever been singles.
And they don't use the SR anyway (?).
Rotating magnet magnetos don't get an entirely good reputation in aircraft either.
When they are good they are good, but when they are not.....
Although the magnetos are obviously different.
An instructor here is a member of the 'twin magneto failure glider club'.
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acotrel said:
So what?
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As far as a Lucas K2F magneto goes, I have 3 bikes with them, all rebuilt mags, never had a failure on any of them. Are there better engineered mags, absolutely! But if it is rebuilt correctly with proper parts, it will probably last a lifetime. I have rebuilt several mags used on various race bikes, a BTH on a late 1920's JAP dirt track bike, an AJS 7R, several racing Norton Dominators with standard K2f's & a K2FC (competition model), 2 BSA Goldstars with MO1 Lucas Magdynos. All race, not one single mag failure.
In my opinion, and based on experience of rebuilding mags that were previously "professionally" rebuilt (the 7R was from NZ, Rod Coleman's bike) often well meaning re-builders are using capacitors that are not up to task. To be fair to them, they have been using the best they could find, but up to about a year ago, there weren't any great options for capacitors for these mags. Consequently the best mag re-builder in the world was using crappy capacitors that were doomed to fail. And as a side note, do not ever buy a NOS lucas capacitor!!!!!!! They have a very short shelf life, and an NOS one is already bad.
In addition, original Lucas parts for mags are thin on the ground & stupid expensive, so we have seen an influx of Chinese & Indian mag parts that were all we could buy sometimes. These parts are inferior & will fail. Over time I have been able to source many new made mag parts (mostly made in the UK) that are made better than the originals . One of the problem parts were cheap, inferior plastic parts like slip rings & pick-ups, the new UK ones are much better than originals, as these use precision cnc machining & better materials than the originals.
So, in closing, I would have to say Lucas K2F mags may not be the best mag in the whole world, but they routinely work for years & years on the road & in racing if rebuilt correctly with good materials. And I will take it a step further for "acotrel", If you are willing to send me your mag & pay postage both ways, I will rebuild your mag for you & will for this mag only offer you FREE labor, a FREE Brightspark Easycap capacitor, FREE cleaning & inspection! Once disassembled, I will be able to tell you what is wrong, & we can go from there.
More than 1/2 the mags I see have 50- 70 year old armature windings, I prefer to rewind every mag I get in to insure long life, unfortunately it adds about $200 US dollars just to rewind the armature.
In my opinion, and based on experience of rebuilding mags that were previously "professionally" rebuilt (the 7R was from NZ, Rod Coleman's bike) often well meaning re-builders are using capacitors that are not up to task. To be fair to them, they have been using the best they could find, but up to about a year ago, there weren't any great options for capacitors for these mags. Consequently the best mag re-builder in the world was using crappy capacitors that were doomed to fail. And as a side note, do not ever buy a NOS lucas capacitor!!!!!!! They have a very short shelf life, and an NOS one is already bad.
In addition, original Lucas parts for mags are thin on the ground & stupid expensive, so we have seen an influx of Chinese & Indian mag parts that were all we could buy sometimes. These parts are inferior & will fail. Over time I have been able to source many new made mag parts (mostly made in the UK) that are made better than the originals . One of the problem parts were cheap, inferior plastic parts like slip rings & pick-ups, the new UK ones are much better than originals, as these use precision cnc machining & better materials than the originals.
So, in closing, I would have to say Lucas K2F mags may not be the best mag in the whole world, but they routinely work for years & years on the road & in racing if rebuilt correctly with good materials. And I will take it a step further for "acotrel", If you are willing to send me your mag & pay postage both ways, I will rebuild your mag for you & will for this mag only offer you FREE labor, a FREE Brightspark Easycap capacitor, FREE cleaning & inspection! Once disassembled, I will be able to tell you what is wrong, & we can go from there.
More than 1/2 the mags I see have 50- 70 year old armature windings, I prefer to rewind every mag I get in to insure long life, unfortunately it adds about $200 US dollars just to rewind the armature.
skipsoldbikes said:
Its hard to imagine how a magneto could be considered 'rebuilt' if it didn't have NEW wire ?
There are new versions of the internal condensor available, for quite some years- several rebuilders locally at least have had them made or sourced. And seen mention by several in your neck of the woods saying the same thing....
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I think the comment about the capacitors is correct. With an SR it is only a matter of carrying a spare, and undoing and retightening two fasteners. With a failed K2F in Victoria, it is take the bike home from the race meeting , waste your entry fees and travel expenses, take the magneto to the 'expert ' in Chiltern and go through the whole process again. I gave the last two K2F s that I had away to a friend. He thought they were lovely - I DON'T. Like Smith's chronometric tachos, they are a waste of space . There has not ever been one Japanese bike made which was fitted with equivalent garbage.
I think a lucas SR is a lot cheaper than this:
http://www.bt-h.biz/twin_mag.htm
I think a lucas SR is a lot cheaper than this:
http://www.bt-h.biz/twin_mag.htm
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Yes Rohan, there have been several condensers with a "similar" rating, but not designed specifically for this application, and they do last for a while, often due to the very limited use they receive. But unfortunately I have had many so called "new" capacitors potted with epoxy in the end of the armature fail. And to make matters worse, they are often overfilled with epoxy to the point of epoxy getting all over the copper windings on the bobbin. Trying to remove the epoxy without breaking the wires is difficult, and sometimes impossible. Regardless of weather the capacitor is placed in the original position inside the bowels of the armature (rather stupid nowadays with the tiny size of modern capacitors), or under the points ( makes far more sense) the key is having the right component for the job. The elusive Panasonic capacitor mentioned on another forum is a non-issue, as it isnt being manufactured any longer. There are at least 2 other "modern" capacitors that I have removed that had failed that had the correct capacitance rating, but they weren't designed for the voltage & pulses of a magneto, hence the early failures. Given the choice of the 2 locations for the capacitor, where would you want yours located, deep inside the armature, or under the points, where they are easy to access?
As some of you know I rebuild BTH & Lucas mags. I also use & sell all manor of parts for both brands. One of the products I use & sell are the Brightspark Easycaps. I only bring this up because that brand of capacitor is made in England by motorcycle enthusiasts. The designer of these capacitors has designed them in such a way as to relocate the capacitor under the contact points & disconnecting the old dead capacitor without having to remove it. See their site:
http://www.brightsparkmagnetos.com/
Most of us who work on our own bikes could handle replacing the old capacitor with a new one under the points (Brightspark model) themselves at home. There are other aspects of a mag rebuild that would need to be done by a a specialist, like remagnetising the magnet, or rewinding the armature.
You are right Rohan, seems like foolishness to "rebuild" a mag & not rewind the armature (in my opinion), but there are several Lucas rebuilt mags on ebay usa right now that state that the armature was not rewound because the did an ohms test & it checked out , so it is OK. Don't believe it !!!! That is one of several tests that would need to be done, & even then, I personal y would want to do the job right & do it once, why would you want to risk being stranded somewhere because you didnt spend the extra money to get your coil rewound????? "penny wise, pound foolish" I say. But having just said that, I have rebuilt mags for guys who said to re-use the old armature windings, and I will, no problem at all, I just wont warranty the mag.
As some of you know I rebuild BTH & Lucas mags. I also use & sell all manor of parts for both brands. One of the products I use & sell are the Brightspark Easycaps. I only bring this up because that brand of capacitor is made in England by motorcycle enthusiasts. The designer of these capacitors has designed them in such a way as to relocate the capacitor under the contact points & disconnecting the old dead capacitor without having to remove it. See their site:
http://www.brightsparkmagnetos.com/
Most of us who work on our own bikes could handle replacing the old capacitor with a new one under the points (Brightspark model) themselves at home. There are other aspects of a mag rebuild that would need to be done by a a specialist, like remagnetising the magnet, or rewinding the armature.
You are right Rohan, seems like foolishness to "rebuild" a mag & not rewind the armature (in my opinion), but there are several Lucas rebuilt mags on ebay usa right now that state that the armature was not rewound because the did an ohms test & it checked out , so it is OK. Don't believe it !!!! That is one of several tests that would need to be done, & even then, I personal y would want to do the job right & do it once, why would you want to risk being stranded somewhere because you didnt spend the extra money to get your coil rewound????? "penny wise, pound foolish" I say. But having just said that, I have rebuilt mags for guys who said to re-use the old armature windings, and I will, no problem at all, I just wont warranty the mag.
Ask Bob Kizer about having condensors made to do the job.
Very highly regarded in his part of the world, it seems.
http://www.podtronics.net/magnetos.htm
Local guy here had them remade to do the job too.
Any amplifier repair store can advise on this, old foil condensors are the bane of old hi-fi equipment too.
Those brightspark ones sound neat, but are only good/rated for a year or 2 ??
Aco needs to find a racing magneto, and someone to do it properly.... ??
Very highly regarded in his part of the world, it seems.
http://www.podtronics.net/magnetos.htm
Local guy here had them remade to do the job too.
Any amplifier repair store can advise on this, old foil condensors are the bane of old hi-fi equipment too.
Those brightspark ones sound neat, but are only good/rated for a year or 2 ??
Aco needs to find a racing magneto, and someone to do it properly.... ??
It's too early to tell how long they'll typically last, Rohan. So far, we have sold over 1500 of them in just over one year. Prior to that, we ran some prototypes for many months on test bikes, and also abused some samples something wicked on our test rig. Out of all of those, we've had only one failure, and that was in the first couple of miles after fitting. We sent the customer a replacement, which he fitted in a couple of minutes.Rohan said:
Compare that with a condenser in the armature that fails a couple of miles after a rebuild (something that does happen occasionally). Mag off, and back to the rebuilder. Armature out and apart. Old condenser out with some risk of damaging the brand new windings. All back together with new condenser. Back on the bike and re-time the ignition. A lot of time and work.
Ken
Brightspark Magnetos
They certainly are easy to fit/replace, that is a bonus.
Foil condensors can last a long time too, of course - they generally fail because the internal paper/wax gets dry spots ?
This can take decades.
Look at all the old military stuff around - and stereos and hi-fi's.
Modern condensor versions are bullet-proof in this aspect ?
Look at all the computer stuff around - power supplies in particular...
Foil condensors can last a long time too, of course - they generally fail because the internal paper/wax gets dry spots ?
This can take decades.
Look at all the old military stuff around - and stereos and hi-fi's.
Modern condensor versions are bullet-proof in this aspect ?
Look at all the computer stuff around - power supplies in particular...
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In some ways, a capacitor has not changed much in over 200 years, since the first capacitors - Leyden jars. Simply, they were glass jars with a wrap of copper inside and outside: 2 conductors separated by a dielectric (non-conducting) material. The initial stage of manufacturing a film capacitor is to start with plastic film, or paper and film, and roll it up with thin aluminium or copper foil. As the film may contain microscopic flaws (and the paper always does), multiple layers of thin film is required rather than 1 layer of a thicker film. This is necessary with high voltage and up to 7 layers of dielectric may be used at one time.
Lucas capacitors use paper, some of the better quality mags ( stereos & Hi-Fi's) used mica, as did most of the early mags, this is why some old mags still have their original capacitor. Because Lucas used paper (cheaper) the capacitors as new only has a 10 year shelf life unused, on a shelf, which is why I don't recommend buying a "new" old stock genuine Lucas capacitor.
Any product can fail, thats for sure, but I can tell you this, I have sold more of these Brightspark easycaps than any other vendor in the world, literally. I also have personally installed many of them in my customers mags. I have not had to replace one yet due to failure. I have replaced a few lost my the post office though
One of the things I liked about the Brightspark capacitors is that their website explains all you would ever want to know about magnetos, no more mysteries in the black art of magneto rebuilding. They have print outs of the step-by-step instructions, blueprints on how to make your own tooling, even copies of the old Lucas parts manuals for mags. This way a "do-it-yourselfer" can give it a go, or do some work themselves & have a mag shop do some of the work (like remagnetize the magnet for example).
Anytime we see a product we are not familiar with, we get skeptical, as we should. But this item has proved itself to me Its the only capacitor I will use on a mag, period.
I figure, even if I had a Brightspark Easycap fail ( sooner or later it is bound to happen) I can replace it in a few minute & for around $20-$30 US dollars, with a screw driver , a wrench, and a feeler gage ( or a business card in a pinch) If I use any capacitor installed inside the armature, I am looking at an all day project, and if one had to pay a bike shop & a mag shop to do that job, I have to think you are looking at around $600 USD or so ????
Lucas capacitors use paper, some of the better quality mags ( stereos & Hi-Fi's) used mica, as did most of the early mags, this is why some old mags still have their original capacitor. Because Lucas used paper (cheaper) the capacitors as new only has a 10 year shelf life unused, on a shelf, which is why I don't recommend buying a "new" old stock genuine Lucas capacitor.
Any product can fail, thats for sure, but I can tell you this, I have sold more of these Brightspark easycaps than any other vendor in the world, literally. I also have personally installed many of them in my customers mags. I have not had to replace one yet due to failure. I have replaced a few lost my the post office though
One of the things I liked about the Brightspark capacitors is that their website explains all you would ever want to know about magnetos, no more mysteries in the black art of magneto rebuilding. They have print outs of the step-by-step instructions, blueprints on how to make your own tooling, even copies of the old Lucas parts manuals for mags. This way a "do-it-yourselfer" can give it a go, or do some work themselves & have a mag shop do some of the work (like remagnetize the magnet for example).
Anytime we see a product we are not familiar with, we get skeptical, as we should. But this item has proved itself to me Its the only capacitor I will use on a mag, period.
I figure, even if I had a Brightspark Easycap fail ( sooner or later it is bound to happen) I can replace it in a few minute & for around $20-$30 US dollars, with a screw driver , a wrench, and a feeler gage ( or a business card in a pinch) If I use any capacitor installed inside the armature, I am looking at an all day project, and if one had to pay a bike shop & a mag shop to do that job, I have to think you are looking at around $600 USD or so ????
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I am willing to put my money where my mouth is here, anyone who is a member of this forum that wants a Brightspark easycap, PM me with what model Easycap you need (or tell me the model of your BTH, or Lucas mag) and i'll give a (approx.) 20 percent discount which includes free shipping to anywhere in the world. So a Easycap model CO1, CO2, CO3, & CO5 will cost you $20 USD, the CO4 will be $24 USD.
I will keep this offer open for the next 7 days. Happy Easter !
I will keep this offer open for the next 7 days. Happy Easter !
Sounds basic, but its very easy to check. My 650ss used to vibrate very badly if the head steady fasteners were anything but done up really tight.
Sort out the misfiring issues as well, that cannot help.
Don,t forget....Occams Razor.......the simplest solution is frequently the right one.
Best of luck
cheers
wakeup
Sort out the misfiring issues as well, that cannot help.
Don,t forget....Occams Razor.......the simplest solution is frequently the right one.
Best of luck
cheers
wakeup
I just welded up the holes on the head steady of my 650ss because they were sloppy. I am going to re-drill them so it is a perfect fit to my specific bike with holes that exactly match the bolts on the engine and frame.
Actually the same should be done to the engine plates of any bike. To get all the holes drilled to the exact size and to match a particular chassis, engine and transmission is a tough one as they have to be in just the right place or you will not get them all in, but it will certainly add to the stiffness of the chassis and also help keep the parts from moving and the bolts from getting loose with vibration as easy.
It is surely one of the details between a bike put together right and one that is merely just put together.
Actually the same should be done to the engine plates of any bike. To get all the holes drilled to the exact size and to match a particular chassis, engine and transmission is a tough one as they have to be in just the right place or you will not get them all in, but it will certainly add to the stiffness of the chassis and also help keep the parts from moving and the bolts from getting loose with vibration as easy.
It is surely one of the details between a bike put together right and one that is merely just put together.
There is an answer to getting equal timings on a Lucas magneto without stoning the cam lobes.The cam ring is usually accurate (unless someone has already stoned it).The main problem is the cam housing,and how square it sits on the main body of the magneto.A shim can fix that.Rohan said:
Explained here at Britbike.com :http://www.britbike.com/forums/ubbt...in=46330&Words=magneto&Search=true#Post421297
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To repeat a post on this thread from Feb. 14th:
Re: 650 Norton Vibration and Balance Factor
by KenF » Fri Feb 15, 2013 4:19 am
I'd be very worried about putting quarter shim(s) under corner(s) of the end housing. It will increase the end float of the armature. That will increase the radial play of the CB end of the armature. That will make the firing points unpredictable. Even if quarter shim(s) are taken out from under the opposite corner(s) of the end housing, the poor old bearing won't be running true. And I can't see how any of this can cure the problem, unless it's some second-order effect.
The reason for uneven firing intervals in a K2F is if the cam ring is not symmetrical about the axis of rotation of the armature. That can be caused by:-
the cam ring not itself being symmetrical, but in my experience that is rare, even with a worn cam ring, unless somebody has stoned it
the cam ring being loose
the end housing being incorrectly machined, but in my experience that is rare
the armature axis not being fixed, either because the end float is incorrect so that there's radial play between the inner race and the outer race, or because the insulator is shot so that the outer race can move in the end housing
the armature axis being off-centre from the cam axis, because the bearing insulator isn't holding the outer race central in its recess.
In my experience, the last reason is usually the one (unless the cam ring is loose).
Ken
http://www.brightsparkmagnetos.com
KenF
Posts: 3
Joined: Wed Feb 13, 2013 8:15 am
Skip Brolund
Re: 650 Norton Vibration and Balance Factor
by KenF » Fri Feb 15, 2013 4:19 am
I'd be very worried about putting quarter shim(s) under corner(s) of the end housing. It will increase the end float of the armature. That will increase the radial play of the CB end of the armature. That will make the firing points unpredictable. Even if quarter shim(s) are taken out from under the opposite corner(s) of the end housing, the poor old bearing won't be running true. And I can't see how any of this can cure the problem, unless it's some second-order effect.
The reason for uneven firing intervals in a K2F is if the cam ring is not symmetrical about the axis of rotation of the armature. That can be caused by:-
the cam ring not itself being symmetrical, but in my experience that is rare, even with a worn cam ring, unless somebody has stoned it
the cam ring being loose
the end housing being incorrectly machined, but in my experience that is rare
the armature axis not being fixed, either because the end float is incorrect so that there's radial play between the inner race and the outer race, or because the insulator is shot so that the outer race can move in the end housing
the armature axis being off-centre from the cam axis, because the bearing insulator isn't holding the outer race central in its recess.
In my experience, the last reason is usually the one (unless the cam ring is loose).
Ken
http://www.brightsparkmagnetos.com
KenF
Posts: 3
Joined: Wed Feb 13, 2013 8:15 am
Skip Brolund
I'd comment that I met my first K2F as a schoolboy, on an old dommie twin.
I knew nothing about bikes, but the waggling on the end of that K2F suggested that all was not well.
The fasteners holding the camring endplate were marginal at best.
And the timing was out between the 2 cyls by about 20 degrees.
Hunting through the 3 spares that came with it, they were worse !
The cam ring in it was quite worn - the flexible 'fixing' of the camring meant that one side took all the wear - what was that about cam rings not wearing appreciably.
The felt wick is supposed to be kept oiled, according to the manual, and I'd say this had never seen oil on the wick.
Fitting another equally but differently worn camring got the timing back about even, and bolting it all down it did run better.
It came in running condition, just, I'd comment, even with the timing so far out.
Lucas recommend in the owners manual a yearly service - this was obviously a little overdue for this K2F.
I knew nothing about bikes, but the waggling on the end of that K2F suggested that all was not well.
The fasteners holding the camring endplate were marginal at best.
And the timing was out between the 2 cyls by about 20 degrees.
Hunting through the 3 spares that came with it, they were worse !
The cam ring in it was quite worn - the flexible 'fixing' of the camring meant that one side took all the wear - what was that about cam rings not wearing appreciably.
The felt wick is supposed to be kept oiled, according to the manual, and I'd say this had never seen oil on the wick.
Fitting another equally but differently worn camring got the timing back about even, and bolting it all down it did run better.
It came in running condition, just, I'd comment, even with the timing so far out.
Lucas recommend in the owners manual a yearly service - this was obviously a little overdue for this K2F.
