The BSA A7-A10 Forum

Technical => Lucas, Electrical, Ignition => Topic started by: Marqs1979 on 06.03. 2015 14:01

Title: No spark
Post by: Marqs1979 on 06.03. 2015 14:01
For about 1 year ago I renovated my k2f magnet with the new breaker new bearings and a EasyCAP capacitor. Now even the engine are renovated but now when I want to try to start i have no spark.Have not had time to investigate as much but I had spark after the renovation. Can I trust the new EasyCAP capacitor do you think? Is Easycap good quality ?
Title: Re: No spark
Post by: Triton Thrasher on 06.03. 2015 14:52
Try new plugs.

Is the magneto armature turning, when the engine turns?

Are the points clean and opening and shutting?

Is the earth brush or brushes free to move?

Are the pickups and slip ring clean and dry?

The test for the condenser is probably to try another one, unless it's internally short circuited.
Title: Re: No spark
Post by: bsa-bill on 06.03. 2015 15:25
Had the same problem with my RGF, so many variables these days with today's fuel being one , plugs wet so easily.
If TT's suggestions all draw a blank then the one thing that I did not try and has been mentioned on this forum by the Maggie guys is the safety screws, I should have tried a thicker washer under them, if they are too close the spark will decided they are a quicker / easier journey than fighting through carbon brushes and spark plug gap, someday when time allows I'll put the maggie back on with another fibre washer under the screws and see what happens
Title: Re: No spark
Post by: duTch on 06.03. 2015 22:27

Are you using a button cutout, or a switch...?  Either way disconnect it and try- but keep it handy for easy reconnect...!!!
Title: Re: No spark
Post by: beezermacc on 07.03. 2015 08:47
Whilst the Easycap is a good idea I find that a significant number of owners do not find the Easycap as easy to fit as they thought. Removing the old capacitor from the circuit requires care, adequate soldering skills, and a little bit of knowledge so that the insulation of terminals is achieved without any danger of the live side coming into contact with the armature. I suspect something may have gone wrong with the Easycap process, probably not the Easycap itself, but something to do with the points assembly or the soldered connections. Unfortunately, as you will have removed the old capacitor, you are not left with many options. I would normally advise people to fit another complete set of points (begged or borrowed) and see if that cures it. In your case you can't do that without losing the capacitor. However, there is a dodge you can try... Fit a completely different set of points and fit an outboard capacitor (old Lucas car distributor type) between the kill connection on the mag and the mag body. Worth a try. If it works you know your problem is with the points.
Title: Re: No spark
Post by: groily on 07.03. 2015 15:02
Beezermacc is quite right.

We say on our site that Initial fitment does, however, involve disabling or removing the old condenser/capacitor. This is a delicate but not particularly difficult task, which we explain in very great detail.
Those were my words back when we started, and I stand by them. It IS delicate, but for people who happily tear gearboxes apart and put engines together and make all sorts of parts for themselves etc etc, I didn't and still don't think the hands-on owner should find it too difficult.
But, because it certainly isn't easy, we go to what some people think are ridiculous lengths to explain what has to be done, to the extent of teaching grannies to suck eggs.

The K2F is the easiest common armature to attack, provided the coil is good of course, because it is possible to disable the old condenser simply by snipping and insulating the low tension live + "link" wire at the condenser end. They are usually accessible, except in some cases where the wires are very short (on rewinds often) and the condenser connections for a modern replacement are buried in resin that is hard to dig out without breaking anything.

Most people who have wanted to do it have done it just fine, including many people on this forum.
The most difficult EasyCap application is for the low inertia steel cb assembly, for which the EasyCap board is a dainty bit of kit designed for two very small capacitors on its wings. The biggest problem owners encounter is the length of the spring blade tail screw on these steel cb assemblies - It mustn't be long enough to touch the 'wrong' metallised side of the circuit board. Cutting/filing down a 6BA screw is a painful job as well - my workshop floor would reveal a few of the darn things that got away.
The second most common problem (not limited to EasyCap installation either!) is fitting the cb with the spring blade kissing the camring - which is fatal on the steel assembly owing to the fact the moving point is 'low tension live'. It's 'earth' on the earlier brass sort, so a kiss won't matter. It will just wear out the spring until it might even break.

It would be ridiculous to claim that anything like this won't ever fail, because of course one will, sometime or another.
However, of over 5000 sold we have had 3 or maybe 4 back. One blew on Day 1 (manufacturing defect, or us getting too enthusiastic with the soldering iron); a second didn't work on the customer machine (magdyno) when another one he fitted did - but I use the first one as a test piece often and it does work fine; and a third had been somewhat manhandled. They're all guaranteed 2 years and I'll always send one out to anyone with doubts, or who wants to test by simple substitution.

I carry a spare on a keyring, but in an aggregate 50K miles probably, on my 'mule' A10 and 2 AMC twins over 4 years, all weathers, I haven't had a problem. I take them off regularly to test them, to see that the capacitance remains within the 10% limit of spec, and that they remain leak-proof to 2 Giga Ohms at 500v. They always have. I admittedly have the advantage that I know the rest of each magneto on which they are fitted is in tip-top shape, but even so, they have already done better than 2 reconditioned armatures that were on 2 of the machines, whose condensers broke down at under 10,000 miles. The motivation for our product was the premature failure of a rebuilt mag on my A, and of the similarly-rebuilt magneto on one of the late KenF's bikes: we reckoned that if things HAD to go wrong, then let them please go wrong in a place you can get at them.  The premature failures both involved the use of one particular brand of commonly-used condenser. We can't, and I wouldn't, condemn anything out of hand - but I know what I avoid, and I have dug out many dozens of them which have suffered the fate of my A and KenF's Rapide.

The problem is that you don't always  know what you are getting, as there are very few trade winders out there, and many suppliers use the same few sources' choice of buried condenser. Nor can 99% of people be expected to be able to tell the differences - until after they break down, in a howling gale and pissing rain, as I did.

Anyone with a cheapish high voltage leak tester can test an EasyCap, and anyone with a simple multimeter with a capacitance scale can test its capacitance. 150nF for the brass cb, 136nF for the steel. Whenever installing one, I ALWAYS hold the cb open on the bench after fitting the board, and measure from backplate to live point - that should show the capacitance. If it just shows 'ohms' and probably squeals at you, then the fitment has gone wrong. This is not a game you can easily play with a buried item not disconnectable from the low tension winding.

Very happy to discuss any particular problems via PM or email, rather than behave like a pernicious vendor here!

Cheers, Bill (with my Brightspark hat on)

Title: Re: No spark
Post by: Marqs1979 on 07.03. 2015 16:36
BSA bill is the one who was right. :-)
I'm a little worried about the points.The shaft as the movable part sits on is pretty worn and the breaker wobbles a bit too much there any good solution to that problem? maybe i should try to drill the hole in the points and make a bush ???
I must say I'm very impressed by the EasyCAP. Very clever solution and with the installation instructions provided it is in my eyes very easy to install:-)but of course you should be a bit handy.
Title: Re: No spark
Post by: Triton Thrasher on 07.03. 2015 17:09

I'm a little worried about the points.The shaft as the movable part sits on is pretty worn and the breaker wobbles a bit too much there any good solution to that problem? maybe i should try to drill the hole in the points and make a bush ???

That's not good. The timing can do funny things at road speed, if the moving point is loose.

If the pivot pin is worn, I wouldn't expect it to still be round, so a bush might not work. Replace the pin, or buy a new points plate. Only the steel kind is commonly available now.
Title: Re: No spark
Post by: groily on 07.03. 2015 17:30
Glad to hear your installation wasn't too bad - that's a relief!

The safety screw gaps should be 6.5 to 7.5mm sayeth Lucas. You can test with drill shanks down the pick-up hole - well, that's what I do anyway.  Then it's washers, or grind the pointy ends. Or find some longer screws sometimes and round off the noses.

Does sound as if you need to make/get a new points pivot post though. You are right to worry a bit because the effect of slop on there can be pretty bad. Often, there will be a haphazard series of not-very-good sparks when the points open, rather than a nice fat one, and it can mess up the firing interval between cylinders and the timing. (As TT just said.)

Sometimes a new set of points may do it (for a while anyway, the post won't be round (as TT also just said)), most times there is nothing for it but to bite the bullet and make/buy & fit a new pivot - or find a better cb backplate. Pivot kits were being sold a while back, not sure if they are now - Beezermacc may have some even!

Cheers, Bill
Title: Re: No spark
Post by: Triton Thrasher on 07.03. 2015 18:22
It's not that I'm clever or anything- it's just that it happened to me.

I've had the pivot pin come loose in a couple of steel backplates too.
Title: Re: No spark
Post by: Marqs1979 on 07.03. 2015 18:59
Will the easycap fitt on this ?
Title: Re: No spark
Post by: groily on 07.03. 2015 19:56
It will - part number C04 for low inertia steel assembly either rotation, C01 for anti-clockwise brass. See
Title: Re: No spark
Post by: groily on 07.03. 2015 19:58
Just enlarged the pic, that's a later assembly of the low inertia sort, so part is C04. Sorry - Specsavers again! Bill
Title: Re: No spark
Post by: Marqs1979 on 08.03. 2015 16:53

Replaces the one Dragonfly my plate? Does it fit?

But I will try changing the pin. Can anyone say what it should have in diameter? Mine is between 3.6 to 3.8 mm and the hole in the breakers is 4 mm (sorry that I write in millimeters, I do not understand better)

Can i make a new pin in stainless steel do you think? Or should it be brass or bronze?

Title: Re: No spark
Post by: groily on 08.03. 2015 18:05
Straight swap, yes, the Draganfly one is the later version, for both clockwise and anti-clockwise drive mags.
There are various dimensions to the pivot post, and they aren't exactly the same for the brass and steel assemblies. There should also be a relieved section for a bit of lube, and the base bit has to fit the backplate snugly. I find that when fitting pattern points on brass cb assemblies the hole in the new moving one often has to be lightly reamed out anyway, so if making something, I'd start with the points that are to be fitted and use drill shanks from a set that goes up in 0.1mm increments to get a good measurement on what has been supplied. The original brass type assembly had a post in copper, but anything on your list would do. The thing with stainless, or most of it, is you can't solder it. A bit of silver steel works very well too. Your old one certainly looks well-used and abused! Cheers, Bill
Title: Re: No spark
Post by: Marqs1979 on 09.03. 2015 20:29
I decided to order from Dragonfly and also a fitting EasyCAP from brightsparkmagnetos because I have so much custom fabrications already that I find it difficult to find enough time.
Thank you all !!
Title: Re: No spark
Post by: Marqs1979 on 17.04. 2015 16:33
At last!! it has been on the wrong track !!! Yesterday it arrived from dragonfly :)
I was confused about the breakers.... is there no way to adjuste the breaker gap ???
Title: Re: No spark
Post by: Triton Thrasher on 17.04. 2015 17:50
Of course the points are adjustable.

Is it a brass or steel backplate?
Title: Re: No spark
Post by: Marqs1979 on 18.04. 2015 14:48

I do not understand where to set the breaker gap
Title: Re: No spark
Post by: Triton Thrasher on 18.04. 2015 15:16
Fit the points to the magneto. Turn the engine until points are fully open. Check the gap.

if it's not 12 thou:-

Slightly loosen the centre screw, which holds the points into the armature's tapered socket.

Loosen that big screw which is visible in your photo. It goes through an oval hole in the bent plate that carries the "fixed" point. You can see the edge of that  hole in your photo.  Move the fixed point to correct the gap. It pivots about the centre.  Tighten the screws and check the gap again.

Page 64 ( I know, it's not all that clear in that book.
Title: Re: No spark
Post by: Marqs1979 on 18.04. 2015 15:21
Thanks :-)
Title: Re: No spark
Post by: WozzA on 19.04. 2015 00:34
are those a new type reversable points?
I've never seen that type B4?
Title: Re: No spark
Post by: wilko on 19.04. 2015 01:03
Give me the brass points any day. This is what happened to the steel backed ones in a Matchy twin.
Title: Re: No spark
Post by: bsa-bill on 19.04. 2015 08:36
are those a new type reversable points?
I've never seen that type B4?

Title: Re: No spark
Post by: Triton Thrasher on 19.04. 2015 09:17
are those a new type reversable points?
I've never seen that type B4?

New in 1960.
Title: Re: No spark
Post by: Triton Thrasher on 19.04. 2015 09:20
This is what happened to the steel backed ones in a Matchy twin.

They are rather paltry.

I've had trouble with loose pivot posts.
Title: Re: No spark
Post by: bsa-bill on 19.04. 2015 09:35
New in 1960.

really, it is a few years ago (mmm could be 8 /9) since I bought a set and thought they were something new then, but tempis fugit and all that
Title: Re: No spark
Post by: Triton Thrasher on 19.04. 2015 11:02
I had never seen the tin points until I found you can't buy new brass plates, to replace worn ones. That was mid-1990s.

After 1959, there were fewer models with magnetos and the UK market collapsed anyway.
Title: Re: No spark
Post by: bsa-bill on 19.04. 2015 11:16
you can't buy new brass plates,

yes, I have a brass set spare, changed it to steel ones when having starting problems with the RGF (higher compression), might have been a backward move as it didn't resolve the (no spark) starting problem, Pazon did so it is ignition, still have the magneto in bits, going to send it to one of our Maggie guys to get checked out (when I remember), it works on the Flash but not on the RGF (as does the one on the Flash if you see what I mean) so probably just needs to be better than good for HC
Title: Re: No spark
Post by: Marqs1979 on 19.04. 2015 16:48

Can someone explain how this part can be bent in this way? Do not understand what I did wrong ?? Is that the same thing has happened with Wilkos ??

I bent it back and then started the engine and went for a little while, then stopped and then became impossible to start. Then I checked the spark position and then it was all wrong again :( It must have changed :( What does that mean? Is it just to tighten the auto advance unit harder or may something else have happened?
Title: Re: No spark
Post by: Triton Thrasher on 19.04. 2015 17:56
If the auto advance has moved on the shaft, the tapered faces may be a bit chewed up.  The pinion should stick readily to the shaft, when you press it on with your fingers.

I've had success grinding them in together with fine valve grinding paste.

I can't see what's up with the bent thing.  It looks like you may have bent the moving point plate, by forcing it to move, with a screwdriver, when one of the two screws was not loose enough. Straighten it. 

It's common to have to bend it so the points meet squarely.

Title: Re: No spark
Post by: groily on 19.04. 2015 18:13
Lucas called the later steel backplate assembly "low inertia". Low cost more like. Don't know about the inertia either, as the force required to open the steel ones can be considerable even if the weight of the rotating mass is less than the earlier type. The advantage is they work for anti-clock and clockwise mags by fitting the moving point one way round or t'other - provided the fixed contact point is on the correct side. Original ones, some of, had a fixed point on BOTH sides of the butterfly, but most sets are anti-clockwise rotation only, with just a rivet (one of the bits that broke on Wilko's) where there could be a second contact for a clockwise mag like on a Vincent, Douglas, loads of cars etc. And that's a fiddly mod too - swapping a rivet for a decent tungsten point in a very confined space. Been there, done that and didn't like.

The worst of the later sets, in my view, is that the opening point is low tension 'live'. So if the spring blade, or the 6BA screw that retains it, kisses the camring on the way round, bye-bye sparks. The brass sets were arranged the other way, so there couldn't be a low tension short circuit (for that reason at any rate).

If the adjustable plate is bent, it might be because the insulator - a small figure of eight-like bit of nylon, usually white-ish, wasn't seated properly. Easy enough to get askew, what with the little register sleeves that go up and down and around. When the plate was tightened up by the two screws, being so flimsy, it could have buckled. It should straighten out with a bit of force.

You'll really curse, Marqs, when you take off the moving point and the spring washer that holds the plot together busts one of its little tangs  . . . .

It would be really GOOD if new cb backplates were available. TT refers to the loose pivot syndrome - which happens to brass sets too and is never good. But there are only e-bay solutions it appears, and who knows what you'll get from there. Last year, I started making a few new backplates for my own purposes, but (like for ATD parts, see other posts) it's a labour of love . . .  and is more complicated than it looks when it comes to broaching keyways and so on. The dimensions are mission-critical for the maintenance of correct internal timing on any mag, and the pain of getting it wrong after spending ages on the tools is hard to describe but I know it well  . . . What we need is a small production turning operation - or better still a small foundry operation with accompanying finishing skills - to get into production with new units of a quality comparable to the brass type. They are a hell of a time-consuming thing to make as a one-off on a lathe and milling machine, although it can be done and I proudly possess one or two (which actually work fine).
It's the old thing: - who is willing to pay what it costs to make these things in pitifully small quantities? For 'cooking' everyday bikes like mine, not me, and I doubt if most classic owners would either. It requires scale Scale SCALE, which we just don't have as far as I can see, or folk like Wassell would have got there it already.

Cheers, Bill
Title: Re: No spark
Post by: cyclobutch on 20.04. 2015 17:20
Or a cheap manually skilled resource pool?
Title: Re: No spark
Post by: Marqs1979 on 20.04. 2015 17:46

I have access to this machine, and believe me without much difficulty can manufacture copies of the brass plates. The only thing I do not know how I'm going to do is the wedge that prevents the plate from rotating in the hole ??

Today I grinded with fine valve grinding paste  up the advanceunit to the shaft and now it seems the machine start and go without interruption
Title: Re: No spark
Post by: Triton Thrasher on 20.04. 2015 19:07
I suspect the key is formed with something like a crimper, or jodler.

A key could be soldered on too, I guess.
Title: Re: No spark
Post by: Angus on 20.04. 2015 20:33
I have no skill or knowledge of fabricating parts but I have been reading about 3d printing and was starting to wondered which parts could be produced using this method. It seams ideal for small runs of specialised parts but not sure of which material would be best and what the wear and stress requirements would be. The process once scanning or obtaining a drawing of the required part appears to be RELATIVELY cheap.
Title: Re: No spark
Post by: groily on 21.04. 2015 07:56
Depends how many you fancy making Marqs, I guess, with that nice bit of kit you show there. (Drool drool.)
One-offs can be done with a bit of time, see pic - the later type being easier to replicate on non-computerised tools etc. Some design mods could be incorporated - screw-in pillars for the pivot being a useful one in my view.
As for the keyway, a little broach will do it as a simple whacking weapon, but a production job would need a careful degree-controlled set up so you could put the key wherever you wanted it for use on different mags - of all makes using ringcams of the same basic dimensions - eg Lucas, Bosch, BTH, some Magn├ęto France, ML etc - for either anti-clockwise or clockwise drive. And as TT says, a blob of solder and a file will do the job to reclaim a damaged one or put something on a blank taper, as long as it's put on in the exact right place to get the optimal internal timing.
The brass type present the additional problem (for a non-professional production environment) of makinjg up the fixed point mounting block, but can also be done if time is no object.
The one here is made in bronze (because I had some the right dia, for no other or good reason) and works fine. The pivot is screw-in and uses a screw to retain the moving point. The worst thing? Making the winged plate for the tail screw for the moving point screw. A dead easy production stamping process, sure, but a pain in the proverbial without.
(The insulator was in fact made on a 3D printer. Not sure what materials can actually be used with them, but plastics won't do it for the main parts angus. However, if it's true that someone made a pistol capable of firing using one  . . . anything's possible!!)
Cheers, Bill