Harley Davidson Model WLA (motorcycle, solo). Service manual (October, 1943) - page 2
LUBRICATION
and blown out through outside breather. However, a moderately driven
engine, making only short runs now and then, and seldom thoroughly
warmed up. is likely to accumulate an increasing amount of water in oil
tank. This water will, in freezing weather, become slush or ice and. if
allowed to accumulate too long, may block oil lines with resulting
damage to engine. Also, water mixed with oil for some time, forms a
heavy sludge of considerable acid content that is very harmful to
bearings and other internal engine parts. To sum it up briefly, an
engine that is used only for short runs during freezing weather requires
frequent oil changes along with thorough flushing of tank to remove any
accumulated sludge.
