If not fingernail catching then IMHO run some Scotchbrite over it sideways and at an angle, like honing. It looks like some coolant was in there and ran down the bore when the piston last moved downward.
Is the motor you are asking about the cam and such?
yes sir it is.I realy dont have extra fund for a rebuild,when i went to here it run,it ran great no noise smoke nothing.I did the scotchbrite just a bit and it did help some.