Not sure if this has been asked before, but suppressed or non-suppressed - which is best to use?

Regards

Pat

email (option): sacombsashtrees@hotmail.com

Hi Patrick.

Non-suppressed only for the magneto.
In fact, some magneto refurbish shops would void the warranty
If suppressed caps are used.

Regards,
Noam.

Unsuppressed. Never use any sort of resistance on magneto HT system. The loading will damage the windings, cost you a rewind. Don't ask how I know. A suppressed cap is about 10.000 ohms, suppressed leads are about 1000 ohms per inch. Years ago you could get suppressed caps for magnetos rated at 1000 ohms. Be careful with spark plugs if R rated they are resistive. If not sure with plugs use a meter and check resistance from the centre electrode to the cap.

Hi Noam

Out of interest what is a typical resistance between the carbon brush and the output end of the magneto HT Pick Up.

Regards

Pat

email (option): sacombsashtrees@hotmail.com

Hi Ian

I liked the "Don't ask me how I know"!

I wont as long as you don't ask me why I'm asking!

Regards

Pat

email (option): sacombsashtrees@hotmail.com

How can you tell what kind of cap you have ?

I think the suppressor caps have it writon on them, or at least there is a reasonable gap between the end of the HT lead and plug top which will indicate the space where the suppression bit is.

Strangely, though we know that a suppressor cap is not good for a magneto. A WD in-line suppressor was fitted to motorcycle HT leads. I guess they thought that wireless interference was more important than mag overhauls

I have these fitted to several of my bikes. But I remove the two brass screws and the carbon brush and springs between them and drill out the bakelite (7mm) so that I can slide and glue it onto the lead as a cosmetic item. Ron

email (option): ronpier@talk21.com

If you are not sure if cap is resistive or not measure for resistance between part that goes on plug to the part the lead attaches to. I think you will find the inline war type suppressors are about 1000 ohms.

Few WD bikes originally had any kind of plug cap fitted to the HT lead.............it was normally just the brass spade connector...........

BSA however, and a few Ariel's, used the KLG waterproof bakelite cover, and the Flea, James ML and Welbike all used the large bakelite "bell-shape" Lodge cap.......

None of these were suppressed.............military thinking of the time, as Ron mentions, dictated the requirement for an in-line suppressor rated at 10,000 ohms for the HT lead, plus on most bikes also a detachable screw-together brass immobiliser....

As Ron mentioned, for an accurate period representation today it is best just to fit the suppressor (drilled out) and the immobiliser outer rubber-cover............aside from any magneto issues, I was always told that any resistance between power source and the plug should be avoided where possible................

And to add to Steve's information. The Lodge cap was also fitted to Royal Enfield WD/CO and WD/G. Here is my WD/G with the complete lead. Ron

email (option): ronpier@talk21.com

I have found a Lodge cap for my Welbike but I was surprised how big the terminal on the plug has to be to fit it it. I do have this WD marked AC plug with a knurled terminal which seems to clip in OK but is this the correct part?

The terminal that is, not the plug.

Rob

email (option): robmiller11(a)yahoo.co.uk

Rob here is my Welbike plug with the little brass top hat that the cap clips onto. This is the only type that I've seen for the Lodge (Bell) cap.
They were also fitted to the Flea and ML. Ron

email (option): ronpier@talk21.com

An eBay seller has been stating that the screw-down KLG caps were fitted to Vincents....No takers at his price though.

https://www.ebay.co.uk/itm/Vincent-2-original-KLG-spark-plug-caps-NOS-/284382549810?ViewItem=&item=284382549810&nma=true&si=epaFiQDAhL10qf7RtlYhDo87V38%253D&orig_cvip=true&nordt=true&rt=nc&_trksid=p2047675.l2557