I've been using an NGK B5ES in the Ariel (spark is thanks to Interspan unit) and was just wondering what everyone is running.

I had a plug break down on Sunday and people are starting to say Champion are better that NGK etc etc.

So I started wondering if the nose is the same would I be any better off using one of the new all singing all dancing plugs or just try a Champion equivelant?

What is the preference NGK or Champion?

Thanks

Generally use NGK Iridium. Not had any problems unless the bike has one.

Only spark plugs I have had fail are Champion, but twice in over 40 years is still pretty reliable

Good blast between sections helps to get the plug up to temp and clean itself,my experience is that a carb set rich fouls the plug which because in most classic trials they are running light/slow they just foul.No plug will stand that for too long.

If you had come to our last trial you could have had a really good blast - shame you took the soft option of big game hunting.

Thanks gents, tried the Champion equivelent of the NGK B4ES at the weekend, very impressed :-) Will keep you posted......

Ken,is that a BTH electronic mag you have on there ? I've been doing some tests since I took my AJS motor apart... Yesterday I mounted the Lucas racing mag up in the lathe and ran it at 300rpm whilst watching the spark output on my scope.I was more than happy with the spark voltage and duration - until I decided to pressurize the bottom of the spark plug with compressed air.(Somewhere handy to compression pressure when running) Then the spark became unreliable,often disappearing completely.When I saw this I realised why its so hard to get a stable idle and the hydrocarbon emissions from it were so high.But the standard biker tests all passed with flying colours - plus it always started first kick etc.....

Think I might be on the phone to BTH when the engine is back in one piece !