History
Carburetion
Ignition System
Lubrication and Cooling
Parts
100

In 1876 this German engineer built the first successful four-stroke internal combustion engine, using a cycle that still bears his name.

Nikolaus Otto

100

In a carburetor, this narrowing in the airflow increases air velocity and lowers pressure, drawing fuel into the airstream.

Venturi

100

his ignition component converts the low voltage from the magneto into the thousands of volts needed to create a spark.

Ignition coil

100

Most small engines rely on this cooling method, where air is forced over metal fins on the engine to remove heat.

Air Cooling

100

This moving engine part travels up and down inside the cylinder to compress the air-fuel mixture before ignition.

Piston 

200

This thermodynamic process—intake, compression, power, and exhaust—defines the classic gasoline engine cycle.

Otto cycle

200

When starting a cold small engine, this device restricts air entering the carburetor to create a richer fuel mixture.

Choke Valve

200

In small engines, this device uses rotating magnets in the flywheel to generate the electrical current for ignition without a battery.

Magneto

200

These ridged metal structures on the outside of an engine cylinder increase surface area so heat can dissipate more effectively.

Cooling Fins

200

This engine component connects the piston to the crankshaft and converts the piston’s motion into rotation.

Connecting Rod.

300

In 1892 this German engineer patented a highly efficient engine that ignites fuel using compression rather than a spark.

Rudolf Diesel

300

This carburetor component maintains a constant fuel level in the bowl by opening and closing a small inlet valve.

Float

300

This component delivers the spark to ignite the compressed air-fuel mixture inside the combustion chamber.

Spark Plug

300

In many small engines, this rotating component doubles as a fan to push air across the engine for cooling.

Flywheel

300

As it rotates, this major engine component converts the up-and-down motion of the piston into usable rotational power.

Crankshaft.

400

In 1885 this German inventor built one of the first practical gasoline-powered automobiles, the Motorwagen.

Karl Benz

400

In small engines, this tiny calibrated opening meters fuel from the bowl into the air stream.

Carburetor jet

400

In many small engines, this rotating engine component contains magnets that pass by the ignition coil to generate current.

Flywheel

400

This lubrication method used in many small four-stroke engines uses a rotating dipper to splash oil onto moving parts.

Splash Lubrication

400

This hollow chamber houses the piston and is where combustion takes place inside the engine.

Cylinder.

500

Introduced in 1908, this automobile helped popularize internal combustion engines worldwide through mass production.

Ford Model T

500

In many small carburetors, this chamber holds a small reserve of fuel and works with the float to maintain a steady supply to the jets.

Float Bowl

500

This safety device stops a small engine by grounding the ignition coil so the spark can no longer occur. 

Kill Switch

500

In two-stroke small engines, lubrication occurs when oil is mixed directly with this fuel before entering the engine.

Gasoline

500

Located at the top of the cylinder, this engine part opens and closes to allow air-fuel mixture in and exhaust gases out.

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