You are best to stick with the oem plug spec then its seems, particularly on the older 2V carbies. But if Iridiums are better for cold starting on ie bikes like an S4 then I'm in. Let's debate!
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Roast Beef Monster!
Termignoni and Bucci - Italian for pipe and slippers!
S4 Fogarty, S4R 07T, 748, Series 1 Mirage