I recently replaced a spark plug and after only about ten miles it failed. No spark at all and when tested with a multimeter, no continuity through from the top down through to inner electrode.
Bought another plug, bike ran perfectly in the workshop so I carried on with other jobs. Went to start bike a week later and no spark. Second new plug failed and again no continuity. Whats going on? Is my engine somehow killing plugs or am I incredibly unlucky to have bought two plugs from a dodgy batch, they are NGK both from the same reputable bike shop. Any ideas?
