Very poor spark on my 350 single

[DeanJordan]

Does anyone know if there is an electronic ignition system to fit my 350 red hunter single 1951 ,I think the armature is had it ,

[SteveShone]

Thorspark - see other post.
https://www.sussexmotorcycles.com/thors ... nlineshop/

Steve

[MarkO]

Have you considered repairing the mag? Peter de Kremer or similar perhaps? Had mine done recently on a Velo MSS and it was a total transformation. 350 quid though so make sure it is the mag giving you problems. Bear in mind that unlike coil ignition, a mag will get you home on a flat battery. In fact, some coil ignition systems need pretty much full voltage to function at all.

[Paul Slootheer]

From experience I know that in many cases the coil is ok but the original capacitor is ‘dead’ and malfunctions. I think it’s worthwhile to try a ‘easycap’. I did and it and it functions realy well. This will only cost you aprox. 15 pounds…
http://brightsparkmagnetos.com/easycap/

[MarkO]

Paul

Quite right, but unless you know what you are doing with a mag, trying an easy cap will cost an awful lot more than 15 quid. The old capacitor needs to be removed, is often buried deep within the mag, and it may not be the root cause of any problem with the mag. Brightspark do have a guide, but it is not for the faint hearted!

I think the first thing to do is establish beyond all doubt that the mag is the source of the problem.

[DeanJordan]

Thanks for the info , we bench tested it off a small 14 v drill and it had a small spark but not good ,when we put it back on the bike ,we could not kick it over fast enough to get a decent spark ,when I put my finger on the end off the ht lead ‘and kicking over I can feel a very faint pulse, but it should be giving me a good belt , carbon brushes,and points , are all good and working correctly; don’t won’t to spend to much money on it as I just want to get it running and back on the road ,we’re it hasn’t been for over 30 years or moor ,

[MarkO]

There is some mag testing information around somewhere. I forget the precise details but at cranking speed between 2 electrodes at @ 5.5mm apart you should get a good fat constant spark. From what you say, it does sound as if it is the mag, but I'd be doing a few more checks nevertheless. Other things to check perhaps - HT lead pickup on the mag, HT lead itself, remove/disassemble the points, dress the contacts and clean everything. Coil ignition conversions are fine enough, but of course you lose some originality and you are heavily reliant on the battery always being charged well from the ancient dynamo and the usually equally ancient regulator.

[Roger Gwynn]

If the mag does not show signs of having been re-built I will rebuild it, even if has a good spark as it is only a matter of a small amount of time before it will leave you stranded in the dark on a cold and windswept moor. I prefer to keep my bikes in original spec so would use a magneto as they work well, when in good condition. I would for example change a reg box for a modern solid state one as the performance and reliability is better.

[dennis.t]

I tried to fit an 'Easy cap' but the wiring to the old capacitor was fried and when connecting those wires to the Easy cap they fell apart. Others may have had more success.
Dennis

[paul.jameson]

Mags for singles are easily and reliably repaired by specialists. I use Tony Cooper in Halesowen who is unlikely to charge you as much as the £350 quoted in a previous post, especially if you make sure he knows you are an AOMCC member.
In my experience, it simply isn't worth doing anything other than getting a single mag fully overhauled. If you rely on the dynamo for a coil based system you need the charging system to work properly and in 50 years of Ariel ownership I have had many, many more failures of the charging system than I have of the magneto. In fact, I think that I have only once failed to get home due to a magneto failure and that was a Square Four magneto - which are vastly more temperamental than the singles type, for various very good reasons.