Re: 6 HP Evinrude Fisherman
1971
Standard piston is 0376994
Standard rings 0378432
You need 2 of each, ring sets are sold per piston, next size up is bore job at
.030 if you need to bore it.
See shop.evinrude.com if you need the next size.
You will also need a head gasket 0306204 and gel seal from your dealer for the crankcase halves.
Cheers