Magneto Condenser

[Charles P]

My car is suffering and the finger of suspicion is pointing at the ML RF4 magneto. 
It's misfiring when hot and seems very down on power, again when hot. Earlier today it stopped sparking altogether for a while when hot. 
It was fully rebuilt a decade ago by the late Tony Holder, so the coils are properly wound modern ones, also being a rotating magnet type, the coils have an easier time. 
My thought is that the condenser (capacitor) is failing. 
Two questions: 
1/ What are the signs of a failing condenser?
2/ Has anyone found a suitable replacement for an ML mag?

Thanks

Charles

[Alan]

The symptoms I had are the same as you describe. I’m using a BTH mag, which may or may not be better depending on your point of view.

[Steve Jones]

When the condenser was failing on the Simms Magneto on my Lea Francis, the symptoms were exactly as you describe, Charles. OK when cold, failing or failed when hot particularly when trying to re-start the engine after a short stop.

Steve

[Charles P]

The symptoms I had are the same as you describe.  I’m using a BTH mag, which may or may not be better depending on your point of view.

When the condenser was failing on the Simms Magneto on my Lea Francis, the symptoms were exactly as you describe, Charles. OK when cold, failing or failed when hot particularly when trying to re-start the engine after a short stop.

Steve

Thanks gents. That's a reasonable diagnosis then

Now, where to get a replacement? 
The condenser on an ML is tucked into a cylindrical hole in the base, so my assumption is that it can be replaced without waiting in the extended queues that every magneto repairer seems to have. 

This is the only possible I've found via Google:
http://www.brightsparkmagnetos.com/easycap/index.htm
Anyone have experience of these people?

Thanks 

Charles

[Hugh Barnes]

Bill Brown at Brightspark was my go to guy for mags, though he himself is now retired, I think. However, he was not the only person in the company so for spares, I wouldnt have any qualms in using them...

[Charles P]

Bill Brown at Brightspark was my go to guy for mags, though he himself is now retired, I think. However, he was not the only person in the company so for spares, I wouldnt have any qualms in using them...

Thanks Hugh

I'll email and see how I get on

C

[Mike Costigan]

Any of these motorcycle condensers any good?

https://www.gsparkplug.com/ignition/condensers

[Charles P]

Any of these motorcycle condensers any good?

https://www.gsparkplug.com/ignition/condensers

Thanks
May do but I'm not sure if there are any differences between coil and magneto ones 

C

[John Cornforth]

Hi

In the short term, a condenser for a coil and points system will probably work fine, and will be better than your failing one. In the longer term it would be better to get one with a lower capacitance value more suited to a magneto, i.e. nearer the 0.15 to 0.20 microfarads range rather than the 0.25 to 0.40 microfarads typical of coil systems.

The mechanical arrangements and wiring (provided it's not crazily long) won't affect the performance, but clearly something made for the job will be tidier.

[A G Wood]

These guys have some interesting content regarding ignition system capacitors in general, and also appear to offer a (temporarily suspended !)  repair service:

https://www.themagnetoguys.co.uk