Following on from my other post.........

It may need a specialist to comment, but what are the differences between modern magneto condensors and the originals ? There were a few originals floating round a few years ago now, sealed in the original wrappings..........

I know it's all down to correct storage conditions, but does age really make a difference if these things have been sealed and stored correctly ?

Why bother with a 50 year old condensor even if they are new old stock. I have just fitted a Brightspark cap to my MO1 magneto for my M20. The starting was getting poor when hot this year. After following the online instructions about cutting out the old condensor and fitting the bright spark cap under the points i could not believe the size of the spark with just flicking the mag backwards and forwards over the magnetic flux. The bike starts first kick when cold and starts easy when hot. Most common magneto problems i have had seem to be the old condensor.
Just Google brightspark magnetos and read up about then. The caps are on ebay for around £15.

Tim W

email (option): t.j.walker@btinternet.com

Just as he says!!!!

email (option): britool51@hotmail.com

I've heard about these.........simple to fit too........how do they work exactly ? Obviously, by enhancing the power of the spark and by-passing the old condensor ??......but presumbly, the rest of the mag needs to be in reasonable order ?? Sorry if I sound thick here.......

Condensers, now called capacitors, have evolved considerably since the wax paper dielectric type used in 60 year-old magnetos. If the old ones haven't failed yet they soon will. Install the new, miniaturized types. They are much more stable and heat-resistant.

Jeff

email (option): jjbandoo@aol.com

Here is the writeup (from a long time ago) from the guy here in the US that rebuilt my magneto, Bob Kizer:

Leaky capacitor. This is the #1 cause for magneto failures. In the case of a magneto the capacitor stores voltage that is created by the collapsing magnetic field in the armature. In doing so, it also prevents the points from arcing or burning when they open. In order for a capacitor to do its job, it must be able to take on an electrical charge and hold it. A leaky capacitor cannot take a charge because the charge is dissipated as quickly as it accumulates. I can guarantee every British motorcycle powered by a magneto is either not delivering maximum spark and/or is on the verge of failing if the original Lucas capacitor has not been replaced. All capacitors made in that era were made with (waxed) paper dialectric, and they will degrade with age.
Lucas (and most other) capacitors made in the 50's & 60's used a paper dielectric. Remember back in the old days when you did a tune-up on your '57 Chev. (or was it a '65 MGB)? Any time you replaced the points, you automatically replaced the condenser.
I've tested NOS Lucas capacitors right off the shelf that are leaky. It's humorous seeing new Lucas capacitors advertised in catalogs at prices that approach $75 ea. Due to the above mentioned characteristics, an original Lucas capacitor is the last thing you want to use. So where is do you get one, Radio Shack? No. Due to the high pulse currents encountered with ignition circuits, special capacitors must be used. (For engineers, the dV/dt rating should be >1000 and the DF <.05%) Capacitors obtained through commercial sources are usually metalized polyester and will fail. If you really want to replace your old capacitor, we have them for "K" models for $10 ea. The single "M" models require 2 ea. @ $8 ea. Guaranteed not to fail.

Eventually all pre-70's Lucas capacitors become leaky. With time and age, the capacitor goes through a metamorphosis- first turning into a resistor, and finally into a conductor, i.e., dead short. That mag that worked great twenty years ago when the bike was parked now emits only a small spark. I've heard people say their mag will shock the crap out of you so it must be good. Wrong! House voltage (110 volts) will shock the crap out of you, and even kill you, but it certainly will NOT spark your spark plug.

Steve,
Yes you need a good mag in the first place, i knew my bearings and bearing insulators were OK as i had replaced them a few years ago. The coil is from the late 50s and still felt hard with no signs of damage but it still had its 50+ year old condensor fitted. On the brightspark notes it tells you how to test your coil, I did not do this as i did not have the equipment to do so. My mag had the same old symptoms of a failing condenser (poor starting when hot).
On some of my other bikes i have had the coil rewound with the newer type condensors fitted in the place of the old Lucas one, if these fail they are a pig to change but the bright spark cap fits under the points and is easy to change. At £15 its well worth a try, but again you have to have a good coil. The brightspark instructions are easy to follow and cover the full process well. I have a spare MO1 on the shelf and i am going to convert this as well, its just a matter of cutting the old condensor out but to do this you have to remove the drive side bearing and slip ring and split the armature, again full instructions are on the brightspark page.

Tim W

email (option): t.j.walker@btinternet.com

Very informative chaps, thank you.......

Presumably, if the Brightspark unit is designed to replace the old condensor, do you still need to isolate this / cut it out of the circuit if it has failed / is failing ?

I note too from their page that the units are good for 4 years or so before a test is required and apart from a guarantee, there has been a very minimal failure rate......

I might just try one........cheap enough !

What are your thoughts on these Ian ?

Yes Steve, you are correct - the old condenser needs to be cut out or isolated from the unit. The B/Spark website goes through how to do this if you don't know the procedure, but are up to tackling it. I am very happy with my B/S conversion so far. One advantage is that if/when the new condenser fails it is a relatively simple straightforward task to fit a new one. They are cheap enough to carry a spare.

['The single "M" models require 2 ea. @ $8 ea. Guaranteed not to fail.']

The above quote from the article in a previous post...

As you can see it IS possible to have a new condenser fitted to a rewound armature that won't fail prematurely...

In answer to your question Steve, I haven't used a 'Brightspark' yet as I'm getting good service from my 'standard' magnetos and don't feel the need to change them at the moment...
Consequently I can't quote from personal experience on the subject.

They appear to be a good idea though and the only drawback as I see it is that many people won't have the knowledge/tooling/ expertise to do the alteration to their armature without a real risk of damaging it...

IMO I think it shouldn't be understated that if you are not confident and/or don't have the right equipment it's probably best not to attempt it...

However, for those with any doubt I think the company offer a conversion service don't they?...After initial fitment any subsequent replacement is easy.....Ian

email (option): ian@wright52.plus.com

Thanks for that informative reply Ian............

Seems that fitament of the Brightspark unit is not as simple as stated as you need to cut-out the old condensor from the armature..........and most rewound units find this coated in resin............am I being unreasonable in thinking that this only involves chopping a wire or two ? Whilst I have the equipment and facilities to pull apart an armature, I don't quite fancy it.........in my mind, I still regard the armature as a sensitive instrument...........and I'm no expert here..........

Despite the favourable cost of the Brightspark unit, and money not being a real object, I can see costs rising IF you need to send the armature away for the process being done correctly..............so perhaps not as cost effective...........

Also, my 16H, built over 20 years ago now with a second-hand armature, always starts hot or cold regardless of how badly stored or little used............and runs very well...........

Guess this is a VERY open area...............

As I said in my post on the other thread on this subject, I did over 70,000 miles on a NOS magdyno that according to received wisdom MUST have had a 'leaky' condenser...

Obviously that was not the case...

However, I guess you could take the stance that the cost of the initial fitting, if done by Brightspark themselves, wouldn't cost as much as a mag overhaul if your windings are sound to start with..

Personally though, I would ignore the doom merchants and fit your NOS armature if it has performed well under a 'load test'...I can't see that you really have much to lose...

Fitting it is going to cost virtually nothing and it may perform well as my NOS magdyno did (I actually had two new ones that both worked OK)...Ian

email (option): ian@wright52.plus.com

Also using a Brightspark unit

Ken there provides great support & upon request will remagnetise the body - an item often overlooked

Funnily enough before I fitted my brightspark - my old magneto began to be a bit erratic, all the symptoms of a condenser but in fact a worn/cracked slip ring

Difficult to diagnose that

Job

email (option): Jonnyob1@googlemail.com

Thanks for all the advice and contributions........as I mentioned in my original post........."two camps"...........

Hi all, to add my 2 cents, and cannot find the old post about this (but seems all part no's on the website have changed anyway, very helpful!!), have fitted these very cheap condensors in all my armatures;





Can be ordered online at all Conrad stores;

http://www.conrad-electronic.co.uk/ce/en/product/459828/MKP-thin-film-capacitor-01-F-630-Vdc-20-Contact-spacing-225-mm-L-x-W-x-H-265-x-7-x-165-mm-Wima-1-pcs?ref=searchDetail

Think it's the above?? (pictures are all the same!!)

But on the other side, have successfully used 2 NOS magneto's on my bikes, and they still are OK! after 3-4000 miles on the road, and start very well, hot or cold.

But I did dismantle them, and put new grease in the bearings etc. and had the armature in the oven (max 125 degrees C.), for a day or so, very gradually heat up and slowly cool down again, to get rid of any moisture.

With the Brightspark one, you have to disassemble, and remove old condensor!!

Hope this helps,

Lex

email (option): welbike@welbxxx.net

The problem with the old Lucas condensers you're talking about is they use paper as the insulator. This is what packs in on them over time, causing leakage or a dead short. If you have a pre 1940 magneto, it might have a mica condenser fitted, mine has. This is a layer of mica, layer of metal, layer of mica, etc so it is very unlikely the mica insulation will fail. The place I use to wind my armatures have told me they will always leave a mica condenser in, as it is better than what is available today.

My 74 year old mag's shellac melted in the heat of slow riding on a very hot day in Normandy this year. I was going to complain to Lucas about it, as I'm sure it should be guaranteed for 75 years I had it rewound and the mica condenser is as good as new. I know that doesn't help anyone with the paper insulated condenser, but I expect most mags reconditioners cut out the mica condenser for a new one, thinking it's better.

I'm having a mag done now that is having the condensers changed. My thoughts are, if it's stripped down that far and being rewound, you may as well put new condensers in. If the new ones last half the time of my other mag, it will out last me. If just the condenser has failed but the winding are testing ok, then it would be easier and cheaper to test out the Brightspark condenser. I would always carry a spare though as I read on their website they're giving them a life of 2 years. I'm not sure I could put up with the mag breaking down every 2 years..! I notice someone said 4 years now, so they might have improved them.

A friend of mine has had a mag rewound, the bike didn't run that well, and after a lot of messing about realised it was the mag. When it was stripped by a different place, they said yes it had been rewound but nowhere near enough windings..!

email (option): horror@blueyonder.co.uk

email (option): t.j.walker@btinternet.com

Experience has shown me NOS Lucas components can work fine but that may not always be the case so you take a chance fitting them...

It is equally clear you take a chance fitting a rewound armature with new condensors..That depends on the condensor spec. and the rest of the job (such as windings in Horrors friends case) being done correctly...

One advantage here though is that you get new windings as well as a new condensor and you 'lose' the old shellac insulation on the windings in the process......

It should also be remembered when comparing costs that a full mag overhaul, as well as condenser and windings, includes bearings, insulation washers, remagnetising the body, a new slip ring, new contact breakers, new pick up and earth brushes, a new clutch spring and washer, new tab washers etc., cosmetic refinishing, new gaskets and shims and new fittings and fasteners as required...and the labour, skills and equipment of the person overhauling it of course...

In other words it's a bit more than a new condenser!!

The Brightspark is cheaper but you don't get all of the above which are additional costs if you want them and should be factored in when making a comparison between the two solutions..

The advantage of the Brightspark is that future replacement is easy and incurs little further cost...

However, you have to do the job yourself and have the skills and tooling to do it and realistically you are likely to have to spend more money than just buying the condenser...(bearings for example or any other worn part...)

All these ways are viable ways of repairing a magneto that can produce a completely reliable unit over a realistic lifespan......and all of them have advantages and disadvantages...

It's really a case that there is more than one way to achieve a particular result...

Also it's about how much you want to attempt yourself and how you decide to spend your money....Ian

email (option): ian@wright52.plus.com

Lex,

these look just what I've been on the lookout for. On another site, a different cap was suggested, but they're only available over here if you place a large minimum order. I'll give these a go, already got a mag stripped ready.

Among this winters projects is a re-magnetiser, which we'll be taking to jumbles hopefully, to do a re-magnetising job for anyone who needs it. It's a bit heavy, but still reasonably portable.

email (option): oldjunk@btinternet.com

Tim,

Next time I might try one (Brightspark), replacement would be a lot simpler, but have not one of my red ones fail yet....

Duncan, check if what you order has exactly the same data printed on them as in my picture, my mag rebuilder/rewinder uses these for over 8 years now, and he told me where to get them.

Cheers,

Lex

email (option): welbike@welbxxx.net

Hi all,

I have Bright Spark caps on two of my M20s. They work extremely well. Dis-mantling the armature is a bit tricky for your first go, but it is pretty straightforward.

You will need to make a bearing puller as that is stuck on pretty tightly. The slip ring often will fall out in to you hand. Be cautious here as it is fragile. Any marring will render it useless.

After the slip ring is removed, you will be able to see the heads of the through screws. These are tiny, so make sure your screwdriver fits well. Remove them, and the capacitor side of the armature can come off. Snip the wires going to it, toss it, and re-assemble.

Easy peasy! I'm in the States, so if you are in Canada or the US, I can rebuild these for you.

email (option): britool51@hotmail.com