4-stroke review

Combustion knock, or more commonly known as ping, is a result of which of the following abnormal combustion conditions?

• Lean air/fuel mixtures

• Pre-ignition

• Detonation

• Engine overload

Which of the following is NOT a function of the piston rings?

• Provide a seal to hold in combustion pressure

• Retain as much oil as possible in the crankcase

• Control valve timing

• Transfer heat from the piston to the cylinder walls

The cycle of operation requires four strokes of the piston: intake, compression, power and exhaust. How many rotations of the crankshaft will occur during one complete cycle?

• One

• Four

• Two

• Six

Which of the following refers to gasoline’s ability to become a vapor?

• Volatility

• Viscosity

• Elasticity

• Flaccidity

Service parts (new or used) sold by an aftermarket vendors may be used as long as they conform to original parts in design and function.

• True

• False

Large horsepower engines require spark plugs with which of the following?

• High heat range

• Low heat range

• Secondary heat range

• Dropping heat range

When does a magneto ignition system produce a spark?

• When AC current flows from the secondary to the primary windings

• When the points are at their maximum open position

• When DC current flows from the primary to the secondary windings

• When the primary circuit opens, inducing current in the secondary windings

A completely blocked fuel filter will stop an engine, but a partially restricted filter can do which of the following?

• Cause the air/fuel mixture to be rich

• Cause the air/fuel mixture to be lean

• Cause the engine to flood with gas

• Cause the spark plug to fail

To verify the ignition system is working properly what tool should be used?

• Spark tester

• Feeler gauge

• Screwdriver

• None of the choices are correct

Which of the following is the correct micrometer reading illustrated in the image?

• .620”

• .626”

• .650”

• .651”