could anybody loan me a mag for my 1952 BSA B31 slack wire advance or even a tight wire mag off an M20 to test to see if the mag I have got has a problem will only start the first time you try it 2 or 4 strokes then the next kick it spits back through the carb as if it is to advance it has been renovated and checked the spark is good I don't think the inlet valve is sticking as there is compression I live in north Kent I would collect within a reasonable distance its puzzling I have been trying everything else thank you roger

email (option): roger.beck@node6.com

Roger I had a similar problem with one of my B33s bike would start after several kicks mag had a good spark but bike always had a hell of a kickback as you had to use full advance to start as it wouldnt start easily on retarded setting (timing set with buzzer and 100% correct).This was a rebuilt mag but I removed it and spun it upon bench to test and found sparking between points.I removed armature and disabled old condensor & fitted a bright spark condensor.Once Mag was fitted and re-timed bike would start easily with ignition retarded hence no kickback.Only conclusion I can make is the old type condensor was leaking or not suitable for purpose.Beware of so called magneto repairs who only farm out the bits for repair then build up the mag then send it back to you.I now only use a guy who does everything himself including rewinds / remagnetising etc.If you can find someone to lend you a good mag all well and good but recheck your own mag first mine looked good until I bench tested it.

There have been a spate of bad carbon brushes around at the moment that leave a trail of carbon all round the slip ring which cause tracking around it , I've had one in that wasn't even run other than to try and start it and it had a trail of carbon round it. There are also a duff batch of condensers on rewound armatures which can leave you completely baffled as it will try to start, but won't run for more than a couple of seconds, I know I fitted one to a Norton Dominator that I'd rebuilt and it caused loads of problems as the bike had lots of unknown parameters such as a new concentric carb fitted, a rewound mag and a completely rebuilt engine, so inevitably you start looking at the cheapest things to check namely your valve timing, compression test etc before you look at the other things. I checked and re checked everything before I came to the conclusion that it was the magneto, I fortunately have have a friendly magneto reconditioners just down the road so I got another mag to try, it fired up second kick!! I spent two days looking at the problem and I didn't really suspect the mag until I'd checked everything else until I was blue in the face. The mag sparked well at the plug so there was no reason to suspect it. I've just had a BSA A10 with a problem with its freshly rebuilt magneto and I suspected the same. My mag rebuilder has just confirmed that he has had two more armatures fail within a very short time so I guess there is a duff batch of them around at the moment.

email (option): davmax@ntlworld.com

Rogers problem is baffling? At one point he sent me his magneto for me to give to my bloke to test. He had it working for 40 minutes under load and it didn't miss a beat and firing at the correct place. But another working mag would prove a point and at least eliminate the mag from the equation Unfortunately I haven't got one to hand that I would trust. Ron

email (option): ronpier@talk21.com

Roger, I have a spare re,coned M20 Mag I could lend you,But loan only, Its not for sale or swap, Pm me about pick up,andrew.h.

email (option): warbikes@gmail.com

I've only had one dud magneto in 45 years! You guys surely are unlucky.

I personally I've not had a duff mag myself, but I work on British bikes all the time and so with working with them all the time you tend to come across all kinds of problems. My mag rebuilder is supplied by someone else who supplies quite a lot of other well known rebuilders as well, so there may well be more duff ones put there.

email (option): davmax@ntlworld.com

I have brought one of the britespark electronic condensers the instructions are not very informative 2 things that puzzle me you take the points off and the rear plate you can see a bearing and a brass cup which the carbon brush earth runs on I understanding that the condenser is under this brass cup I assume you need to pull the bearing off but will the brass cup just come off easily or are there wires connected to it I don't want to break anything your knowledge will help me thanks roger

email (option): roger.beck@node6.com

Most of the time condensers go open circuit so fitting a Brightspark unit would mean no stripping of the magneto. On the rare occasions that you get a short circuit then you would need to strip down the magneto.

email (option): iandot clare1at virgindotnet

I'm still using standard spec Lucas magnetos..
Over the years there have been a few cases of defective/incorrectly specified components in the market but on the whole the Lucas units still give good, reliable service after an overhaul...

I have had over 500 units overhauled in the last 20 years or so and have had failures at very low percentages...Also, some of these failures have been mechanical, not electrical...

There are alternative electronic units and things like the Brightspark condenser to consider but I would caution against assuming that a standard magneto is no longer a viable option...

That certainly isn't my experience ...Ian

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

my magneto had a good spark I could stretch it to just under an inch and still have a good blue spark but it wouldn't start the bike it would only give 2 firing stroke the first time you tried to start it then any further kicking would produce nothing come back the next day and the same would happen again for the price of the britespark I thought I would give it a try

email (option): roger.beck@node6.com

Just bought an old maggy yesterday for 50 bucks at a swap meet. cleaned the points fitted a pickup and a monster spark came out. I'll stick to old used ones any day!!

Sorry to hear, Roger, that you didn't find the instructions very informative. Our email acknowledging your order, the packet containing the EasyCap, and the accompanying schematic drawing, all refer customers to the very detailed instructions on our web site at http://brightsparkmagnetos.com/condensectomy. I suggest you have a look there.

All the best,

Ken
http://brightsparkmagnetos.com

Afraid I have to disagree with you Ian. Of the two hundred or so duff magneto condensers that I've replaced in the last year, only one as far as I recall had gone open circuit. The vast majority go very leaky when exposed to the voltage pulse of a few hundred volts when the points open, i.e. they're verging on a closed circuit. It is therefore necessary to disconnect the old condenser, otherwise adding another condenser in parallel with it simply results in a combined effect of a leaky condenser of the wrong capacitance, which will make matters even worse.

Cheers,

Ken.