Pre-ride Check

[MikeB]

It's only a partially sealed system. Every engine uses some oil as it combusts the very thin oil film left on cylinder walls after the compression stroke. If an oil film were not left there you would have a glowing hunk of metal pretty soon.

That might be very little consumption when the engine is new, but the amount of oil consumed increases with age. Unlike humans, engine have increased tolerances as they get older.

[beatswalkin]

I do what I call a 'pre-flight check' each time I ride, before I head out:

Tire pressures;
Fluid levels, including checking for leaks;
Turn signals, brake light;
Headlight and taillight;
Throttle, clutch and brake controls;
Plus a general look around the bike to ensure there's nothing amiss.

Even my 50cc Vespa get the treatment...