KLG HS3 plug

Chris,

Try The Green Spark Plug Company.

They are very helpful, and have large stocks of old/obsolete plugs.

www.gsparkplug.com

01477 532317

Regards

Roger Hainsworth

Sadly, it has taken me ten years to come up with an answer to this, and far too late to be of any use to poor old Chris, but I've just acquired an HS3. It was recommended for road-going Nortons in the 1926 KLG listings. It's actually just a straightforward short (1/2") reach 18mm plug, presumably capable of dealing with what KLG used to refer to as a 'a fair amount of heat' and consequently less resistant to fouling than some others.

It's a typical detachable mica KLG of the period with a substantial 0BA connector thread and a single earth contact.