Whow - hadnt thought of that outcome - thanksI think they miss, but you will never get them out again once the exposed threads coke up.
NGK Spark Plug B6HS | NGK Stock Code 4510 | Sparkplugs Ltd
never use plugs longer than correct size . right ones are best . I always apply an anti-seize compound to part of threads on plugs. nickel is better than copper when using steel to aluminium threads! electronic ignition is only way to go these days. easy enough to get kits or an entire dizzy .