Lots of folks have apparently been listening to alot of old wives' tales! That engine must be run on 24:1 fuel/oil mixture, as per the manufacturers directions. That is a plain bearing engine and plain bearing engines have to have the extra oil. You will not foul plugs. The ones that recommend less oil are the ones that will not be around when your engine loses crankcase pressures and vacuums from worn piston skirts and cylinder walls and possibly a rod through the side of the block. Extra oil will also promote better sealing, more horsepower (through better sealing) less carbon as the piston can transfer heat to the cylinder walls faster and thus will run below the temps that hard carbon or coking develops. When OMC developed engines that ran on a 50:1 mix or variable ratio oiling (VRO) they also developed pistons with more silicon in them or high sil pistons plus, in some engines, a cam-ground piston. These pistons are much harder and were designed to minimize wear with less oil. Your engine was in production long before those developments came about. If still in doubt, do a little research on Gordon Jennings, the Godfather of two-stroke development. He absolutely lays waste to lean oil mixtures and ran controlled testing to back that up versus someone who knows someone who knows someone who ran 50:1 in their vintage, non-replaceable engine, and got away with it!