Do the Saito AAC engines have a ring or lapped? I have a new FA 30S Golden Knight and just flipping it seems like the normal ring type of compression. I know all FS use blowby to lub the bottom end so the fit is like a worn-out engine to begin with. Just curious if they use some kind of ring with a controlled amount of blowby.

Best,   DennisT

AAC does not mean ringless. Saito chromes the aluminum jug in AAC engines. Only a handful of four stroke engines were ever made ringless. The very first FA-30, FA-40, FA-45 (late 70's ?) with bolted head instead of the jug cylinder, Enya 35-4C of the same era, and the more recent OS FL-70.