Well, waiting for the replacement I ordered which will match the hole depth better I feel, I put in an old NGK I found in my bits and pieces, , probably 20+ years old lying around, it is 5/8 hex, it is 19mm reach, looks about same centre-electroide heat-range length, but it is some series NGK which has a thin needle-pointed centre electrode.
the one I took out, which may or may not be OE, was ARCHER A941P..
Anyway, thing started 1st pull, ran faultlessly..stutter/cough/miss when sudden throttle-up and black smoke-puff seems gone even.
Makes me reluctant to now try new one I ordered on Temu for $2.90 all-up which is en-route....
