The Johnson HD-25 parts manual shows the number
for piston rings as part # 43-78.
Is there an updated number?
Not sure I’m going to throw much money in these little HD’s,
but thought if I came along a good deal on rings
I might try them on one and see if it upped the compression
just enough for it to idle better.
Probably a temporary fix at best, but just "thinking".
Thanks.
Anytime you see one of those old numbers, eliminate the – or letter, or whatever. Then pad it with enough zeros up front to make it a 6-digit number. In this case, 004378. Then you have to go to a price list to see if it has been superseded. It has. It changed to 378410 ring set.