My question piggy backs off this one but is re: the spark plug size. I read somewhere that the socket size was 13/16, so I bought that one. When I slide it over the spark plug in the mower, the socket was too big, but the socket fits perfectly around the new spark plug. I bought the BPR5ES as that's what seemed to be the one recommending since it's for a lawn mower, not power washer. I'm wondering if the BPR6ES and BPR5ES require different socket sizes? That's the only thing I can think of why my socket is too big for the one in my mower and fits just right on the new one. It seems like a 11/16 would fit, but I haven't been able to find that size spark plug socket everywhere I've looked. Thanks!