1. wait till it breaks
   annual checks
2. regular maintenance

It is best to service your small engine regularly. That way you can rely on the machine to work. You'll also save time because you only need to shop for parts and take the engine apart once and you can catch potential problems earlier.

1. air
   water
2. refrigeration

Combustion and friction produce heat that can damage the engine parts. To prevent this, air is used to cool the engine and lubricant is used to reduce the amount of friction.

1. Disconnect the spark plugs.
   Drain all the gasoline.
2. Put the car in reverse so it can’t accidentally run you over.

It’s best to disconnect the spark plugs before working on an engine.

1. a damp rag
   engine cleaning solution
2. baking soda and a wire brush

Battery cables and terminals should be cleaned with a little baking soda and a stiff wire brush.

1. meltiness
   life expectancy
2. thickness

Viscosity is the thickness of an oil, grease, or other lubricant.

1. block
   bearings
2. turbocharger

Wear parts, such as bearings, wear out as part of their function and are designed to be replaceable.

1. Contact the manufacturer.
   Throw it away and buy a new one.
2. Post on Reddit.

If you have trouble with a repair, many equipment manufacturers can provide copies of their products’ repair manuals.

1. The engine may be burning oil.
   The catalytic converter could be on fire.
2. Your exhaust fluid reservoir needs to be refilled.

White or blue exhaust is a sign that the engine is burning oil.

1. magneto-powered and battery-powered
   battery-powered and throttle-powered
2. mechanical-breaker and rechargeable-battery

Magneto-powered and battery-powered are both examples of ignition systems.

1. force of gravity
   centrifugal force
2. air pressure

A governor controls the speed of an engine by returning the engine to a set speed when it is slowed by a heavy load. A mechanical governor uses the centrifugal force of the engine's weight to measure the load on an engine; an air vane governor uses air speed from the rotating flywheel to determine the load.

1. controls the amount of fuel moving through the lines
   controls the amount of air entering the fuel
2. controls the amount of throttle the driver can apply

A choke controls the air entering the air-fuel mixture.

1. preps the fuel system for replacement
   preps the fuel system for storage
2. turns the fuel from gasoline into water

Fuel stabilizer should be added to the fuel when a vehicle or piece of equipment is being stored, to prevent damage during storage.

1. never
   a week
2. a month

Untreated gasoline breaks down after about a month, which causes starting or running problems.

1. oil
   water
2. air

Gasoline is a combustible liquid that burns really slowly unless it is mixed with something else to make it extremely explosive. Four-stroke engines mix gasoline with air, two-stroke engines mix gasoline with oil.

1. the throttle
   the carburetor
2. the muffler

The throttle controls the speed of the engine by controlling the amount of gasoline-air mixture that is delivered to the engine. The carburetor mixes the correct proportion of gasoline and air and the muffler mutes the noisy sound of the engine.

1. a battery
   a magnet
2. electricity

A mechanical breaker ignition system uses electricity to provide a spark. A magneto-powered ignition system uses magnetism and a battery-powered ignition system relies on a battery.

1. the flywheel
   the crankshaft
2. the connecting rod

The flywheel, a round-shaped, weighted wheel, delivers the engine's power to the various parts of the machine (e.g. the wheels, the blades). The crankshaft moves the piston up and down in the cylinder via the connecting rod.

1. after every 25 hours of use
   after every 45 hours of use
2. after every 60 hours of use

You should change your engine oil after every 25 hours of use. Most small engines come with a service chart, which helps you keep track of which parts need to be serviced when.

1. a metal mesh screen
   disposable, pleated paper
2. a plastic sediment bowl

In-line fuel filters are usually made of disposable pleated paper, which should be replaced when cleaning the fuel system. Other engines have a fuel strainer in the bottom of the fuel tank, or a removable sediment bowl type strainer in the fuel line.

1. oil bath and dry
   paper and metal
2. dry and metal

Air cleaners keep particles in the air from blocking the carburetor. There are two types: oil baths, which can be cleaned and dry cleaners, which must be replaced.

1. one
   two
2. three

There are three types of carburetors that are usually used in small engines: natural draft, downdraft and updraft. These describe the direction of air flow from the inlet to the engine.

1. one
   three
2. six

An internal combustion, gasoline-powered engine has six systems: fuel, exhaust, ignition, combustion, cooling, and lubrication. Each of these systems has many components.

1. It will damage or destroy it.
   It will slow the engine down.
2. It will use up large amounts of fuel.

An incorrectly adjusted governor will damage or destroy an engine by causing it to operate at excessively high speeds. All governors operate differently, so read your service manual to see how to correctly adjust yours.

1. 0.1 to 0.2
   1.26 to 1.28
2. 1.9 to 2.1

The density of the liquid electrolyte in each battery cell in a conventional battery should be 1.26 to 1.28. If it measures less than 1.25 on a hydrometer, it needs to be recharged.

1. 2, 000 volts
   5, 000 volts
2. 10, 000 volts

A new spark plug requires 5, 000 volts to work. An old spark plug can require double as much.

1. special mixing bowl provided by the manufacturer
   any non-metal mixing bowls
2. a vented gas can only for mixing purposes

Two-stroke engines are lubricated by mixing oil and gasoline. You can buy a premixed product, or mix it yourself using a vented gas canister that is set aside for mixing only.

1. 20-30
   50-60
2. 80-90

Some engines require that their parts be lubricated using lubrication grease, a high viscosity petroleum products. Most lubricating greases have a viscosity of 80-90.

1. 500 degrees Fahrenheit (260 degrees Celsius)
   2, 800 degrees Fahrenheit (1, 538 degrees Celsius)
2. 4, 500 degrees Fahrenheit (2, 200 degrees Celsius)

An internal combustion engine reaches about 4, 500 degrees Fahrenheit (2, 200 degrees Celsius). Therefore, an engine's cooling system is an essential component of its functioning.

1. through petroleum
   through air
2. through electricity, in a similar way to a refrigerator

Most single-cylinder engines are cooled by air that is generated by fan blades on a flywheel. This system is easy to service; it just needs to be cleaned of debris.

1. a leaky or blown gasket
   fouled spark plugs
2. a missing engine shroud

Many problems can cause an engine to overheat, such as a gasket that needs to be replaced.