RE: 4 cycle lubrication
I have found that it is wise to always check the valve settings, even "new out of box" as I have found some not properly set. Again, after the first hour of running, it is wise to check again as initial wear can cause some change. After that, I only check if engine performance is changing for the worst.
Another thing to watch for on 4 strokes, if you use after run oil, it needs to be injected into the crankcase in order to do any good. The bearings that need the protection are located there and putting after run oil into the carb or glow plug hole does little if any good.