1. Two-stroke
   Four-stroke
2. Either

Motorcycle engines tend to be either two-stroke or four-stroke. Some bikes employ Wankels or electric engines, as well.

1. HEMI
   V8
2. Internal combustion

Non-electric motorcycle engines are internal combustion engines. They follow the same technical specifications as automotive engines.

1. Front
2. Rear

Almost always, a motorcycle engine drives the rear wheel. Power is sent to the driven wheel by shaft, chain or belt.

1. 4
   5
2. 6

A motorcycle engine has a gearbox with up to 6 ratios. You'll generally only find reverse gear in heavy tourers or sidecar bikes.

1. Hand-lever
   Foot pedal
2. Small button

You change the gears on the motorcycle using a foot pedal and manual clutch. The earliest motorcycles employed hand levers for changing gears.

1. Yes
2. No

Some motorcycles do have automatic or semi-automatic gearboxes, but these are not as common. Gearheads like to do things for themselves.

1. V-twin
   Single V
2. No V

V-twin engines have been common since the 1920s. Their capacities are generally 850 cc or more.

1. Combustion
   Diesel
2. Steam

The first motorcycles were powered by steam engines. The earliest example of this is probably the Michaux-Perreaux steam velocipede of 1867.

1. Popper
   Roper
2. Steinway

After the French model, the American Roper became the next most popular steam engine. It was introduced in 1869 and was sold throughout the early 20th century. The inventor, Sylvester Roper, apparently died of a heart attack while riding his invention.

1. Back of the frame
   Center of the frame
2. Front of the frame

Nearly all modern motorcycles have the engine in the center of the frame. This became standard between 1900 and 1910.

1. Fastest
   First
2. Last

The Daimler Reitwagen is considered the world's first motorcycle. It used the Otto cycle gasoline internal combustion engine.

1. Yes
2. No

As clean energy becomes more popular, we're seeing more electric engines on motorcycles. These are registered as motorcycles or scooters.

1. Germany
   Canada
2. The U.S. military

Diesel motorcycles are great in terms of fuel economy and military logistics. The USMC has ordered new diesel bikes, known as M1030 M1s.

1. Air
   Water
2. Oil

Most motorcycle engines on the road today are air-cooled. They also use small displacement.

1. One
   Two
2. Three

The majority of bikes have single-cylinder engines, both two-stroke and four-stroke. These are simple, affordable engines that are popular in the U.S.

1. Larger
2. Smaller

In wealthier parts of the world, including the U.S. and parts of Europe and Asia, you see more large displacements and multiple cylinders. In general, you see more variety in the kinds of engines on the road.

1. Diesel
   Gasoline
2. Ethanol

Almost all production motorcycles have gasoline-driven engines. Gone are the days of steam engines!

1. Two-stroke
2. Four-stroke

Due to strict emission laws, there are fewer two-stroke engines on the road each year. Motorheads are taking a hit for the environment.

1. Yes
2. No

Rotary engines have never fully caught on for motorcycles. The Wankel rotary bikes are currently not in production.

1. Air
   Liquid
2. Oil
   All of the above

Motorcycle engines can be cooled by all of the above. That being said, today's motorcycles are predominantly cooled by air.

1. Perpendicular
2. Parallel

When engines are mounted transversely, the crankshaft is perpendicular to the frame. Transversely mounted engines are suited to have belt or chain final-drive.

1. Perpendicular​
2. Parallel

When engines are mounted longitudinally, the crankshaft is parallel to the frame. Longitudinally​ mounted engines are suited for shaft final-drive.

1. Two-stroke engines
2. Four-stroke engines

Two-stroke engines have fewer moving parts than four-stroke engines. They also produce twice the number of power strokes per revolution.

1. Two-stroke engine
2. Four-stroke engine

Two-stroke engines are more powerful for their mass. They offer stronger acceleration, but similar top speeds.

1. Two-stroke engines
2. Four-stroke engines

Unfortunately, two-stroke engines have a shorter life. This is due to poorwe piston lubrication from the fuel-oil mix than four-stroke engines.

1. Two-stroke engines
2. Four-stroke engines

Four-stroke engines are associated with a wider power band, This makes them somewhat gentler in terms of power delivery.

1. Two-stroke engines
2. Four-stroke engines

Four-stroke engines have better fuel economy. This is because they have more complete combustion of the intake charge.

1. Cylinder heads
   Valves
2. Pistons

The hottest parts of the motorcycle engine are the cylinder heads. They require adequate cooling, using air, oil or liquid.

1. Potheads
   Airheads
2. Boneheads

Some BMWs are known as airheads, thanks to the cylinder-head type. Airheads are air-cooled flat-twin engines.

1. Panhead
   Butthead
2. Buckhead

The panhead engine is associated with Harley-Davidson. It gets its name from the distinct shape of the rocker covers.

1. Oilhead
   Snakehead​
2. Rockhead

Another engine type associated with BMWs is the oilhead engine. These are different from airheads because of their oil-cooling.

1. Oval Head Valve
   Overhead Valve
2. Olive Hued Valve

Overhead valve, or OHV, engines have valves that are operated by pushrods. Similarly, overhead camshaft engines have overhead camshafts.

1. Together
2. Seperate

Originally, engines and gearboxes were separate. The gearbox was driven by a primary chain. Later designs combined the two.

1. Different
2. The same

In the motorcycles of today, the same oil is circulated through the engine and the gearbox. In earlier models, different oil was used for each.

1. V-twin
   Flat-twin
2. Parallel-twin

It all began with Edward Turner's 1937 Triumph Speed Twin. This parallel twin engine was the most common type for British motorcycles until the mid-1970s​.