I still haven't flown the motors I have , one day soon, but I was just at a mates workshop and he'd bought plugs for a vintage Kawasaki 2 stroke he has (widow maker). Plugs are BH8S. I said to him that what my paramotors use. Then he shows me on the NGK packet, they put an X through aircraft and microlight. BH8S was what I've seen recommended on here and elsewhere, so why the X on the packet? Somewhat confused.