small engens

Pistons in most four-cycle engines have __ rings

3

Grade 8 bolt has how many marks on its head

6 MARKS

When a piston is at the bottom of its travel, it is said to be at

BOTTOM DEAD CENTER

Switch that shuts off a tool when operator releases the control button

DEAD MAN

What are the three groups of carburetors can be categorized into based on airflow through the air horn?

NATURAL DRAFT, UPDRAFT, DOWNDRAFT

Measure engine speed

TACHOMETER

The process of cutting new threads in a hole is called

TAPPING

The process of cutting external threads on an external cylindrical surface is called ____.

THREADING

A two-stroke engine performs the same cycle of events as a four-stroke engine during one revolution of the crankshaft

TRUE

An internal combustion engine burns the air-fuel mixture inside the engine itself.

TRUE

If a four-cycle engine is not operated in the upright position, it may not receive adequate lubrication.

TRUE

Magneto systems produce the current needed to fire the spark plug without an outside source of electricity.

TRUE

Never fill the fuel tank while an engine is running

TRUE

Pistons must have enough clearance in the cylinder to allow for expansion.

TRUE

Safety is the responsibility of everyone in the small engine shop

TRUE

Increases air velocity and reduces pressure by restricting the carburetor's air passage.

VENTURI

On a standard micrometer, each small mark on the sleeve represents

0.025"

In a four-stroke engine, ___ piston strokes occur during each crankshaft revolution.

2

In a two-stroke engine, ___ piston strokes occur during each crankshaft revolution.

2

Compressed air used for cleaning should not exceed what psi level?

30 PSI

The ignition system must be capable of generating ___ volts to force electrical current across the spark plug gap.

30,000

At normal engine speed under normal operating conditions, the proper air-fuel mixture ratio is typically what

ABOUT 15 PARTS AIR TO 1 PART FUEL

The pressure reduction in the carburetor does what

ALL OF THE ABOVE causes fuel to flow from main nozzle to airstream, lowers boiling point of fuel, increases speed of airstream

Torque specifications are given

ALL OF THE ABOVE in inch-pounds, in foot-pounds for critical parts

The process of breaking gas into tiny drops and mixing with air.

ATOMIZATION

Which is NOT a part of the basic magneto ignition system?

BATTERY (spark plug, coil and switching device are a part)

Which of the following is NOT an advantage of a solid state ignition system?

BREAKER POINT REPLACEMENT IS INFREQUENT (advantages include: adjustments not required, spark plug life increased, spark plug timing is automatic)

Colorless, odorless gas produced by a running engine

CARBON MONOXIDE

The spark plug ___ carries the high voltage current to the spark plug gap.

CENTER ELECTRODE

Process of recutting damaged threads

CHASING

Gas engines transform __ into __.

CHEMICAL ENERGY, MECHANICAL ENERGY

Restricts airflow into the carburetor to enrich air-fuel mixture.

CHOKE SYSTEM

As engine speed increases, a governor will

CLOSE THE THROTTLE

During the ___ stroke, the piston moves upward in the cylinder while both valves are tightly closed.

COMPRESSION

Check for a leaking head gasket, stuck valve or excessive ring wear

COMPRESSION TESTER

Piston rings provide a seal between the combustion chamber and the __.

CRANKCASE

The engine block section that contains the crankshaft is called what

CRANKCASE

As the piston moves up and down in the cylinder, the connecting rod rotates what?

CRANKSHAFT

In a four-stroke engine, valve timing is measured in degrees of ___ rotation.

CRANKSHAFT

The connecting rod connects the piston to the

CRANKSHAFT

A telescoping gauge is used to measure

DIAMETER OF A BORE

A ____ wrench is used to tighten or loosen a hex socket-head screw

DRIFT

primers increase air pressure in the float bowl, forcing fuel up the main nozzle.

DRY BULB

A threading tap is used to cut external threads on a shaft

FALSE

All engines have friction-type main bearings.

FALSE

During the compression stroke, the piston creates a partial vacuum that helps draw the air-fuel mixture into the cylinder.

FALSE

Materials with a low flashpoint are difficult to ignite

FALSE

Safety glasses are recommended when working with chemicals

FALSE

The ignition coil's primary winding contains many turns of heavy-gauge wire.

FALSE

The piston must fit loosely in the cylinder.

FALSE

The ring located in the uppermost position on the piston is an oil control ring.

FALSE

The spark plug wire connects the output of the coil's primary windings to the spark plug.

FALSE

The valve stem is the hottest part of the valve

FALSE

To provide an accurate reading, micrometers should be closed as tightly as possible around the object being measured

FALSE

___liquids should be stored in a closed safety containers.

FLAMMABLE

Type B fire extinguishers are designed for use on

FLAMMABLE LIQUIDS

Lowest temperature at which a combustible metal will produce a combustible vapor

FLASH POINT

Maintains a constant fuel level within the carburetor.

FLOAT SYSTEM

The most common type of nut

HEXAGON NUT

Gas produced when a battery is being charged or discharged

HYDROGEN

The ___ in a magneto system operates like a transformer to produce the high voltage needed to jump the spark plug gap.

IGNITION COIL

The carburetor venturi

INCREASES THE SPEED OF AIRFLOW AND DECREASES PRESSURE

During the ____ stroke, a partial vacuum draws the air-fuel mixture through the intake port and into the cylinder.

INTAKE

Gas engines are classified as ___ combustion engine.

INTERNAL

A vacuum carburetor

IS ALWAYS MOUNTED ON TOP OF THE FUEL TANK

The connecting rod forms a link between the piston and the

JOURNAL

Used to prevent motion between a shaft and a gear or pulley that fits onto it.

KEY

Recondition valve seats

LAPPING STICK

Delivers fuel to the venturi when the engine is operating at speeds above idle.

MAIN DISCHARGE NOZZLE

The purpose of a carburetor float is to

MAINTAIN A CONSTANT FUEL LEVEL IN THE FLOAT BOWL

OSHA regulations require employers to provide employees access to material safety data sheets for the hazardous ____ encountered on the job

MATERIALS

A centrifugal governor adjusts engine speed based on

MOVEMENT OF FLYWEIGHTS ON THE GOVERNOR GEAR

Power tools, engines under load and engines running in an enclosed area are sources of excessive

NOISE

Matching Materials with Class of Fire

Oil CLASS B Electric motor CLASS C Wood CLASS A Magnesium CLASS D Gasoline CLASS B

The piston ___ is used to attach the piston to the connecting rod.

PIN

Each ignition spark must occur when the ____ is at exactly the right place in the cylinder during the correct stroke.

PISTON

Pressure created by burning gases in the cylinder pushes down on the top of the

PISTON

The location of the ____ in a two-stroke engine determines the timing of the intake, transfer and exhaust functions

PORTS

Switching devices are used in the ignition system to control the ____ current to the ignition coil.

PRIMARY

The purpose of a choke is to __ for cold engine starting.

PROVIDE A RICH MIXTURE

Install a piston in the cylinder

RING COMPRESSOR

Install new rings on piston

RING SPREADER

Never take unnecessary ____ to complete a job.

RISKS

The unthreaded portion of a bolt near its head is called the

SHANK

Each piston ___ is identified by the job it performs.

STROKE

Movement of a piston from one end of its travel to the other

STROKE

Regulates the amount of air-fuel mixture entering the cylinder.

THROTTLE SYSTEM

Offset portion of the crankshaft from the centerline of the main bearing bore to the centerline of the connecting rod journal

THROW

A C-clamp type valve spring compressor can be used to compress valve springs on L-head engines

TRUE

A deadly amount of carbon monoxide can accumulate quickly in an enclosed space

TRUE

A dial indicator has a movable bezel that can be rotated to set the needle to zero

TRUE

A four-stroke engine uses valves to control the flow of gases into and out of the cylinder.

TRUE

A screw extractor is commonly used to remove fasteners that break off below the surface of the hole

TRUE

A two-stroke engine is generally smaller than a four-stroke engine

TRUE

The valve head transfers heat through the valve seat to the cylinder block.

TRUE

When a piston reaches the top of its travel, it is at top dead center.

TRUE

in an overhead cam engine, both the camshaft and the valve assemblies are located in the cylinder head.

TRUE

Flat ____ provide a wider bearing surface for a bolt head or a nut.

WASHERS

A ____-type feeler gauge should be used to measure spark plug gap

WIRE

Safety glasses (or goggles) should be worn when using

aLL OF THE ABOVE (hammers, drills, compressed air)