Lubrication basics
What is lubrication?
The process of reducing friction between sliding surfaces using a slippery substance.
What is one job oil performs to help engine startup?
Permits easy starting.
What does SAE stand for?
Society of Automotive Engineers.
How are 2-cycle engines lubricated?
By oil mixed with gasoline.
What type of system uses a dipper to splash oil?
Splash lubrication system.
What is friction?
The resistance to motion when two dry surfaces rub together.
Why does oil help prevent rust and corrosion?
Because water forms during combustion and oil protects engine parts.
What does viscosity measure?
The oil’s resistance to flow/ thickness
What does a 16:1 ratio mean?
16 parts gas to 1 part oil.
What does a constant level splash system improve?
Maintains a more consistent oil level.
What are the three forms of lubricants?
Dry (powdered), semi-dry (grease), and liquid (oil).
What additives help oil keep engine parts clean?
Detergent/dispersant additives.
What does the “W” in oil grades (like 5W-30) mean?
It indicates the oil is suitable for low temperatures (winter).
Why should automotive oil not be used in 2-cycle engines?
It can foul spark plugs and leave harmful residue.
What is the purpose of a positive displacement oil pump?
To circulate oil directly to needed parts.
Why is oil the most important lubricant in small engines?
It is often the only lubrication the engine needs.
Name two additional jobs of oil besides lubrication.
Cooling engine parts, sealing combustion pressure, preventing foaming, or aiding fuel economy.
What do the letters “S” and “C” represent in API classifications?
S” for gasoline engines and “C” for diesel engines.
Where can you find the correct fuel mix ratio?
On the engine label or in the manual.
What is weems' favorite food?
What is corn?
How does oil reduce friction between moving parts?
It creates a thin film where molecules roll over each other like tiny ball bearings.
Why is preventing foaming important for oil?
Foam reduces lubrication effectiveness and can damage engine parts.
What is a multigrade oil?
Oil that meets viscosity requirements for more than one grade (e.g., 5W-30).
Why must fuel be mixed in a separate container?
To ensure proper mixing and safety (never mix directly in the tank).
What happens if the oil filter becomes clogged in a full flow system?
A relief valve opens to allow oil to bypass the filter.