1. 2
   8
2. 6
   12

When you think of small engines, the first thing that should pop into your mind is a two-stroke engine and probably one that you would find on a motorcycle. Modern small engines are not only two-stroke, however. Many auto manufacturers have introduced three-cylinder engines over the last few decades.

1. A muscle car
   A dirt bike
2. A pickup
   A family sedan

Two-stroke engines are almost as old as the automobile itself. And yes, the most likely place to find one would be in a motorcycle. But not large motorcycles, more those ones that sound like souped up sewing machines! That said, two-stroke engines deliver a fair amount of grunt and have excellent power-to-weight ratios.

1. Karl Benz
   Henry Ford
2. Dugald Clerk
   Nikolaus Otto

Although two-stroke engines had been seen before Dugald Clerk's design, he was the first to build a two-stroke engine with in-cylinder compression like we know today in modern engines. His design is considered to be the world's first proper two-stroke engine.

1. 1934
   1971
2. 1800
   1878

A Scottish engineer, Clerk invented his in-cylinder two-stroke engine in 1878. He applied for and was given a patent in 1881 for his design. Clerk's engines were not that small, however, as they needed an additional pumping cylinder.

1. Distributor
   Crankshaft
2. Spark plug
   Glow plug

Much like any other engine, a small gasoline engine works in exactly the same way as its larger counterparts. And that means the fuel/air mixture entering the cylinder needs to be combusted while it is compressed. And to do that, a spark plug is needed.

1. True
2. False

The two-stroke engines that are found on scooters and small motorcycles are not water-cooled. Why should they be? With the engine exposed, a motorcycle two-stroke engine is a perfect powerplant to be air-cooled.

1. Fins
   Radiator
2. Fan
   None of the above

Some motorcycles engines have special fins on the cylinder barrel and the cylinder head. This clever design means the engine is kept cool with the minimum of fuss, as air can penetrate deep within it to keep it running at the right temperature.

1. Lawnmower
   Power saw
2. Drill
   None of the above

An almost perfect example of a small gasoline engine would be the one found in your fuel-driven lawn mower. This two-stroke engines have one job only, to turn the blade that cuts the grass. Simple, yet effective, these engines can be a little noisy!

1. Take it for a service at your car dealer.
   Make regular checks of the engine and its parts.
2. It's not a car engine, it doesn't need a service.
   None of the above

Although it isn't a car engine and certainly not as sophisticated, the engine in your lawn mower will still need regular checks to ensure you keep it running for years. This means checking the oil level, replacing the spark plug from time to time and checking the plug gap often as well as keeping the engine clean from grass after you have mowed the lawn.

1. Turns rotational energy into heat energy
   Produces mechanical energy from heat energy
2. Makes linear motion into perpendicular motion
   None of the above

Just like any other engine, a small engine like a two-stroke has one job. And that is to turn the energy produced by combusting the air/fuel mixture into mechanical energy. Although there are many parts that are needed to do this, it all starts with the crankshaft.

1. 5.9-liter V8
   1.0-liter EcoBoost three-cylinder
2. 3.9-liter straight six
   Electric engine

In 2012, Ford released a three-cylinder engine, the 1.0-liter EcoBoost. Co-developed by German company, FEV Engineering as well as Japanese automaker, Mazda, the 1.0-liter is turbocharged and can produce 123 brake horsepower!

1. Helps with the combustion of the air/fuel mixture
   Cleans air entering the engine
2. Cleans gasoline entering the engine
   None of the above

The cleanest air possible is needed in the engine where it is mixed with gasoline and combusted. To achieve this, it is first passed through the air filter where any potentially harmful particles and debris (think small pieces of leaves, for example) are removed.

1. True
2. False

Air filters must be cleaned and replaced whenever needed. Just think about it, any kind of filter will get clogged up with the dirt it is filtering. An air filter is no different. Removed large pieces of debris every so often and replace the filter when need be. This is normally done during a car service.

1. A rag dripping in oil
   Water
2. A wire brush to scrub them and baking soda to clean them
   None of the above

Baking soda is a brilliant general purpose cleaner! To clean dirty battery terminals, use a wire brush and some baking soda. This will ensure that they make proper contact with the battery at all times.

1. Carburetor
   Air sensor
2. Breather
   None of the above

A breather is the part of your car engine that draws air into the crankcase. It is filled with various filtering systems to help keep oil mist and other vapors from entering the air filter. Usually a pipe, it also releases trapped gases in the compartment of the engine.

1. How heavy they are
   How thick they are
2. How expensive they are
   None of the above

When talking about viscosity in liquids, it has to do with their thickness and consistency. For example, water is not as viscous as oil. In engines, oil is used to lubricate the moving parts within the engine. Without it, metal would grind on metal. For this reason, oil needs to be very viscous.

1. Exhaust valve
   Carburetor
2. Tailpipe
   Tappet

An exhaust valve is found in the cylinder head. It is driven by the camshaft and releases exhaust gases after the combustion of the air/fuel mixture. These gases are super hot and the exhaust valve is one of the hottest places in an engine.

1. Head
   Skirt
2. Cylinder
   None of the above

A piston is made up of a few parts including the skirt, head and ring grooves. The cylinder is not part of a piston, however. It is the sheath in which the piston moves and where the combustion of the air/fuel mixture takes place.

1. Cambelt
   Spark plug leads
2. Fan belt
   Rocker arm

The spark plug leads conduct the electrical current from the ignition coil to the spark plugs. This then creates the spark to start combustion within the engine, exploding the air/fuel mixture.

1. Yes
2. No

In 1959, the Mini Mk 1 was introduced to the world. And what a popular car it proved to be! The first Minis had a range of motors with the smallest a mere 848 cc fas engine. This little engine pushed the Mini to a speed of just over 70 mph.

1. Allows gasoline into the engine
   Pumps water from the radiator
2. Creates a seal between the piston and cylinder
   None of the above

In any engine, including a small engine, the compression ring is extremely important. It is tasked with providing a tight seal between the piston and the cylinder. This helps the air/fuel mixture to be compressed effectively, as well as ensuring the combustion of the air/fuel mixture is as effective as it should be.

1. Crankshaft
   Camshaft
2. Flange
   Bearings

Some parts in an engine, even a small engine, will wear with usage. Bearings are one such part. Their main bearing is tasked with holding the crankshaft in place and will wear over time. From time to time, therefore, it will need to be replaced.

1. Consult a professional or the manufacturer.
   Throw it away and get a new one, they're cheap anyway.
2. Take it apart and build it back up, that will solve the problem.
   None of the above

If you have ever messed around on an engine, a two-stroke gasoline engine that drives a lawn mower should not be too difficult for you to maintain. That said, if you come across a problem that you are unsure of how to fix, consulting a professional or taking it to the manufacturer is your best bet.

1. Connecting rod
   Flange
2. Rocker arm
   Gungeon pin

The pistons in a small engine connect to the crankshaft, just like they would in a larger engine. The part that connects them is called a connection rod and it joins the piston at two points, usually. If a connecting rod breaks, a mechanic will usually tell you that you have "dropped a rod".

1. Battery
   Air filter
2. Oil pump
   Radiator

If your car's engine is turning over sluggishly when starting, or nothing happens except for a ticking sound, it's likely your battery is the problem. That is always the first place to check. Luckily, small engines do not need big batteries to turn them over.

1. Manifold
   Cylinder
2. Valves
   None of the above

A small engine is no different from a V8. When the air/fuel mixture is compressed by a piston, it is done within the cylinder itself. There are just fewer cylinders than you would find in a large engine, that's the only difference.

1. Filters the gasoline
   Filters the oil
2. Circulates engine coolant and dissipates the heat from it when it returns to the radiator from the engine
   None of the above

A radiator dissipates the heat that engine coolant carries from the engine into it. It then circulates the now-cooler engine coolant back into the engine to do the same again.

1. Lobes
   Valves
2. Rings
   Pistons

Each camshaft has lobes on it that serve a very specific purpose. As the camshaft rotates, these lobes open and close valves which let the air/fuel mixture into the engine and let the gases out after combustion.

1. Pumps fuel into the engine
   Circulates oil around the engine
2. Controls the air component of the air/fuel mixture
   None of the above

In older two-stroke engines, those with carburetors, you would find a choke. This was used to restrict the air entering the engine, enriching the air/fuel mixture when the engine started. Modern engines that use valves have no need for a choke.

1. Fuel
   Oxygen
2. A mixture of air/fuel
   None of the above

The air/gasoline mixture is ignited by the spark from the spark plug, prompting the combustion necessary to keep the engine running. In a two-stroke engine with a carburetor, the amount of air entering the engine is regulated by the choke on startup.

1. True
2. False

When you compare the intake valve to the exhaust valve in a small engine, well actually any engine, you will find that the intake valve is bigger than the exhaust valve. Why? Well, the exhaust valve is one of the hottest parts within the engine as it lets out superheated gases.

1. Tappet
   Starter motor
2. Air duct
   None of the above

When you turn the key in your ignition, the starter motor engages. It turns the engine over, starting it. A faulty starter motor means the car won't start. Sometimes, a stater motor can jam and a simple tap with a hammer can get it working again.

1. Once every 10 years
   After 25 hours of use
2. After 100 hours of use
   Never

Although it uses far less oil than a small motor car engine, a lawnmower engine still needs oil to help lubricate mechanical parts. This should be changed after every 25 hours of use, as over time, the oil will lose viscosity and not lubricate as efficiently as it once did.

1. Engine home
   Cylinder block
2. Crankcase
   None of the above

An engine block is the part of the engine that houses many of the critical pieces that make a car's powerplant tick over. This includes parts such as the cylinders, valves and pistons, to name a few. An engine block can also be called a cylinder block.

1. 250cc engine
   3.0-liter V6 engine
2. 1.8-liter straight-four engine
   999 cc gasoline engine

Mini cars have a certain charm, and perhaps the most famous of them all is the BMW Isetta. Interestingly, this was not a BMW design but built under license. BMW built the Isetta between 1955 and 1962. It was powered by a 250 cc four-stroke engine.