Magneto on 1938 16H

G'day Billy,

If the Mag is original, that makes it 74 years old!

The internal capacitor (Condenser) will be shot and while you may be able to'mechanically' service the Mag, the permanent magnet will be very weak too.

Suggest you bite the bullet and take the unit (andprobably the dynamo too) across to a reputable magneto expert who will be ableto restore unit better than new, revitalise the magnet and get you nice fatreliable sparks, otherwise you will be going no where fast.

Have a look here, about 1/2 way down the pageyou can click on Lucas Mag manual and download as a PDF. That should get youstarted:

http://www.arielnorthamerica.org/resources.htm

Also have a look here for info on Mags:

http://occhiolungo.wordpress.com/2010/07/12/how-to-magneto-rebuild-2-capacitorscondensers/

http://www.davelindsley.co.uk/default.html

http://www.oldengine.org/members/diesel/magnetos/PetrolMag.htm

Good luck, I have a 1940 WD 16H under restoration herein Adelaide.......

Rgds Steve

No worries Billy, plenty of experts here and real solutions.

Good luck with the restoration and how about a photographic diary for the Roadholder?

Rgds Steve

Following the above - I am in an almost exactly similar situation also with a 16H of the same year (in the UK). Does the team think - when I do get the mag refurbished, can I or should I obtain new magnets made from modern materials? As I understand it, a prewar mag will lose a great deal of its magnetism if the armature (keeper) is removed even for a very short time (so how do they assemble them?...), whereas by the 1950's they were not quite so sensitive. The 16H has a magdyno.

Rare earth magnets are presumably out of the question, are they?

Thanks for any views and experiences.

Hi Bill

Suggest you look up Brightspark Magnetos - they can sort all your problems and not charge the earth.

regards

Derek Ambler

Hi.

The magnetos are remagnetised after reassembly and with the armature in place. Keepers don't really make a difference as you can't get them in there quick enough. The magnetism is lost instantly when the armature is taken out. We remagnetise the old magnets and it's surprising how much life you can get back into them, certainly enough for a fat juicy spark! I've never had any experience using newer materials but if the old mag is reassembled and magnetised properly there is no need for them.

Lucas used paper condensers that absorb water and even NOS ones don't work now! So they are always replaced with a new equivalent.

A well overhauled mag should be a fit and forget part of the bike! So I would recommend getting it done.

Hi Billy, I realise you are new to restoration, but, there is absolutely no connection between magneto and battery. Unless, of course, you change to electronic ignition. The magneto will then no longer provide a spark, but, it just provides the drive shaft for the trigger unit. If you are in no rush to get the bike running, "Brightspark" should be able to help, at a sensible price. Regards, John.

Thanks, Andy - another question answered.

Previously wrote:

Hi.

The magnetos are remagnetised after reassembly and with the armature in place. Keepers don't really make a difference as you can't get them in there quick enough. The magnetism is lost instantly when the armature is taken out. We remagnetise the old magnets and it's surprising how much life you can get back into them, certainly enough for a fat juicy spark! I've never had any experience using newer materials but if the old mag is reassembled and magnetised properly there is no need for them.

Lucas used paper condensers that absorb water and even NOS ones don't work now! So they are always replaced with a new equivalent.

A well overhauled mag should be a fit and forget part of the bike! So I would recommend getting it done.

Thanks, Andy - another question answered.

Previously wrote:

Hi.

The magnetos are remagnetised after reassembly and with the armature in place. Keepers don't really make a difference as you can't get them in there quick enough. The magnetism is lost instantly when the armature is taken out. We remagnetise the old magnets and it's surprising how much life you can get back into them, certainly enough for a fat juicy spark! I've never had any experience using newer materials but if the old mag is reassembled and magnetised properly there is no need for them.

Lucas used paper condensers that absorb water and even NOS ones don't work now! So they are always replaced with a new equivalent.

A well overhauled mag should be a fit and forget part of the bike! So I would recommend getting it done.

I agree, that if properly set up, a mag will last a good long time. As to the condensers, it is true, that the type of condensers that Lucas used were not of the best quality & only had a shelf life of 10 years if new & unused, so any original condenser out there is on its last leg. There are are replacement condensers out there that work much better than the original, I prefer the Brightspark type. During testing, the others I have checked have atendencyto be "leaky" compared to the Brightspark, and to replace the other types, you have to not only remove the mag from the bike, but then completely disassemble the mag to get to the condenser. The Guys at Brightspark have designed a clever tiny little circuit board that mounts under the ignition points for super easy servicing in the future. In addition the Brightspark unit is very inexpensive, and an average home mechanic can do the conversion, or Brightspark can do it for you if you like.

As tore magnetizing, I have been researching this for several months now and have spoken to 6 different magneto guys and have gotten some different answers. 1/2 the shops insist that the magnetos should bere-magnetized assembled, the other 1/2 say they have done readings with a gauss meter & have found the magnetic loss of recharging the magnet in the case, without the armature in place is minimal. I have an original Lucas magneto repair manual & it showsre-magnetizingthe case without the armature in place. So I guess the jury is still out on that issue, but just to be on the safe side, when I am rebuilding a mag, I get it recharged with the armature in the case.

One of the other issues is the coil, there are several bench tests you can do to the coil, but sometimes all checks out OK, & after assembly it produces a big blue spark, but under compression it may fail, or after 15 minutes of use it may fail, so for me, If a coil passes all the bench tests with mymeters, I assemble everything & put the mag on a test rig (on my lathe) and run it at speed for 30 minutes with a homemade gap made out of 2 fixed brass rods in place of the spark plug set up at 7 mm. If all is still good, I will re-use the coil. Or if you want to be pro-active and be sure you have the very best, just get the coil rewond & you wont have to worry about it, but be prepared to spend around 100GBP for a coil rewind.

The slip ring will at a minimum need to be cleaned, &possiblyreplaced, clean the surface of the armature where the brush rides, check the bearings & either re-grease, or replace if required. When assembling the end float (clearance) is critical & adjusted by shims on the armature behind the races & by shims on the case.

There is much more information on the process on the Brightspark website for free at : http://www.brightsparkmagnetos.com/

If done up correctly you wont have any worries about having enough spark, good luck !!!!!!!!!!!!!!!!!!!!!

Skip Brolund

I totally agree with Skip concerning the magneto's. I sent my Lucas K2FC, and aLucas k2Fto Brightspark, andthey both had issues of an extreme nature, and these so called rebuilt magneto's had only covered very fewmiles, and they were rebuilt by experts. NOT.The motors would be difficult tostart from cold on the kick start, and rarely when hot. Brightspark took them apart, added their Easycaps and sorted out all the newnow leaking capacitors, and made them work as they should. I shall be fitting the K2FC to my Nomad, so now i can use it as Norton intended it to be used, out on the road, and not locked away in a shed due to its awfull starting hot or cold.

I have recieved my reports on both of my so called rebuilt magneto that we rebuilt by two so called magneto specialist. Both of them needed extensive work on them. Go to Brightspark, and do not waste your money on these other so called experts as you might as well go out and burn your money. My Lucas K2FC had only done about 140 miles, and the starting of the 99 twin was bloody awful. When Brightsparktook it apart the so called new capacitors were now leaking, and the slip ring was not even held on properly, and that original rebuild was not cheap. Its a no brainer really.

I have two other so called new and rebuilt magnetos from both of these two magneto specialists, and i am going to send them both to Brightspark before i even put them on an engine. I have another Lucas K2FC,that i am going to use on my 1961 Manxman and that is going to Brightspark before i even use it, as i am that fed up with rubbish magneto rebuilders, taking my money and not delivering on what they say. I can take this a stage further. So how would you like to be in an ex RAF aeroplane at 2500 feet and both, and i mean both of your magnetos fail, and you have to do a dead stick landing and hope and pray you do not get killed in the process?

As Ken at Brightspark said recently , problems with a properly built magneto are usuallycarburetorrelated.

Just removed the mag from 1936 16H. It's been in a dry store (inside a house) for at least 30 years, and indoors mostly before that. We tried to start it a few weeks back but no go - albeit we didn't try everything in great detail, but just assumed the mag needs a refurb. It has almost certainly never been touched since it was built - and certainly for 30 or 40 years.

This evening I put it in a vice on the bench with a spark plug strapped onto its body - and span the armature with a power screwdriver. And there are lots of bright blue sparks across the plug...now I wonder if I'm wasting time and money getting it looked at.

Did they have paper or mica capacitors in Lucas M01 magdynos in 1936? And I wonder what's the chance of it all working anyway? I am wondering if the starting issues (after 30 years standing still...) are more to do with the carb...or if high pressure in the cylinder will snuff out the spark.

I suppose it's all guesswork at this stage.

Magneto RepairsMerlins MillToadsmoor RoadBrimscombeSTROUD, Glos.GL5 2UG

Telephone: 01453-886849 (office hours 10 to 12.30, then 2 till 5, Monday to Friday,

http://www.magnetorepairs.com/index.shtml

Sorry about the double post, it said error so I went back and re-posted, then it's here twice and no way of deleting (that I know of). Either that or you lose everything you've written and have to type it out again.

Many thanks for this. I've already arranged to drop it off to Brightspark - but if as you sayits condensor is 'bullet proof' I don't want to 'improve it', do I? I think I'll get it re-magnetised (it is 76 years old!) but the bearings feel perfectly smooth. My friend tells me that the shellac has been known to melt on bikes brought back into service after many years. 'Melt', as in 'flowing out and gluing the mag solid' (hence apparently siezing up the engine!). I feel like the Chief in 'Asterix the Gaul' - always worried that the sky might fall down even if it never does!

You can't really tell if the bearings are ok just by feel. Mine felt ok with no play but the outer race at the points end was pitted. It would have probably gone on for 1000's of mile, but obviously I changed it. Yes the lacquer on the windings can fail, 70 years for original windings is way past what it was expected to do. Mine looked and tested ok so I'll worry about that if it happens. If it did melt as you say, it wouldn'tseize up going along, but more than likely the windings would short and the bike stop.

I think I would talk to Brightspark and see what they have to say about the mica condenser, I'm sure they'll leave it in if you wanted.

There is a lot of "hear-say" written about magnetos. Some fail, after a short time, others seem to go on for ever. Last year, I sold a BSA B31 to my nephew. This bike has been in my family since bought new, by my brother, in 1950. Apart from new brushes, nothing has been touched on the mag/dynamo in 68 years! I never had any problems with my '53 Dominator 88, but that was only 5 years old when I sold it. On the other hand, the mag on my current bike ('54 88) has been nothing but trouble. Maybe "Brightspark" could have solved the problems However, I did not want the hassle of sending the mag to the UK, and possibly being off the road for 2-3 months. In my case, "Thorspark" was the best solution. Early days yet, but the bike is now running perfectly, if it does fail, the mag can still be sent to "Brightspark" as it is still intact.