I have a SA 5w with 8,000 miles I think. Soon after I got it I greased the bearings with Krazy synthetic. I thought the 10w30 lawnmower oil was too thin, so I found this Wynn's old motor additive to make it more clingy. Mix about 1 to 4 parts oil. It works great with only a fly speck of wear. It goes 3,000 miles easily. The grease does wander around inside and ooze out some towards the drum brake. Otherwise, I don't think oil loss is a problem at all. The indicator chain shaft does get oily.

When assembling, I use a 1/2" paint brush to get it all wet including the shell inside. I put a small spoon full of oil for the bath. Did the same for my new RD3 this year.