admitted -- when I worked in a small engine repair shop years ago
seems that at times different plugs were put in
and -- never saw an engine come back in for repair with hole in piston
but -- I didn't work there that long
anyway -- while down the mountain a while back at the local small engine shop
wanting to buy a plug -- the guy had one that would fit
but -- said that it also may burn a hole in piston
this guy's been repairing small engines for a very long time