Small Engine Parts Identification. Fuel Tank -Holds the fuel for engine consumption -Sometimes houses Carburetor -Usually has a shut off valve -Can house.

Small Engine Small Engine Parts IdentificationParts Identification

Fuel TankFuel Tank

-Holds the fuel for engine consumption-Holds the fuel for engine consumption-Sometimes houses Carburetor-Sometimes houses Carburetor-Usually has a shut off valve-Usually has a shut off valve-Can house a screen that can become -Can house a screen that can become

impermeable due to varnish or trashimpermeable due to varnish or trash

Air CleanerAir Cleaner

Separates debris from air taken in during Separates debris from air taken in during operationoperation

Does NOT separate water!Does NOT separate water! Affects engine performance & lifeAffects engine performance & life Most cost effective service part found on any Most cost effective service part found on any

engineengine May use a pre-cleanerMay use a pre-cleaner Various shapes and sizesVarious shapes and sizes Constructed of many different materialsConstructed of many different materials

CarburetorCarburetor

Mixes fuel with air to provide a combustible gasMixes fuel with air to provide a combustible gas Depending on specific application a carburetor Depending on specific application a carburetor

may be Up-draft, Down-draft, or Side-draftmay be Up-draft, Down-draft, or Side-draft Can be found on fuel tank, but….Can be found on fuel tank, but…. Will always be fixed to an intake manifold that is Will always be fixed to an intake manifold that is

fixed to the cylinder head or blockfixed to the cylinder head or block May have multiple jets or “barrels” that regulate May have multiple jets or “barrels” that regulate

fuel consumptionfuel consumption Will have either manual or electric chokeWill have either manual or electric choke

Spark PlugSpark Plug

Part of the ignition system that Part of the ignition system that provides a “spark” to ignite fuel/air provides a “spark” to ignite fuel/air mixture during powerstrokemixture during powerstroke

Commonly misunderstood and Commonly misunderstood and misdiagnosed partmisdiagnosed part

Comes in many lengths and heat Comes in many lengths and heat rangesranges

Not all spark plugs are created equalNot all spark plugs are created equal

ArmatureArmature(Coil)(Coil)

Induces an electric current when Induces an electric current when rotated around a magnetic fieldrotated around a magnetic field

Always mounted in respect to Always mounted in respect to flywheel locationflywheel location

Common ignition source of choice for Common ignition source of choice for newer carbureted enginesnewer carbureted engines

Replaced breaker points ignitionReplaced breaker points ignition

Combustion ChamberCombustion Chamber

Volume of the cylinder above the Volume of the cylinder above the piston in which combustion takes piston in which combustion takes placeplace

Located mainly in the cylinder headLocated mainly in the cylinder head

CamshaftCamshaft

Shaft containing lobe (cams) that Shaft containing lobe (cams) that open and close valves as the shaft open and close valves as the shaft rotatesrotates

Controls engine timing (advance, Controls engine timing (advance, Retard)Retard)

Rotates in conjunction with the Rotates in conjunction with the crankshaftcrankshaft

Connecting RodConnecting Rod

Rod that connects the piston to the Rod that connects the piston to the crankshaftcrankshaft

Large end – crank end (end w/bolts)Large end – crank end (end w/bolts) Small end – piston endSmall end – piston end Attaches to piston via the wristpin Attaches to piston via the wristpin

CrankcaseCrankcase

Housing for the crank, cam, etc.Housing for the crank, cam, etc. Base of the engineBase of the engine Contains engine oilContains engine oil Seal housingSeal housing

CrankshaftCrankshaft

Main shaft of the engineMain shaft of the engine Provides the reciprocating motion of Provides the reciprocating motion of

the pistonthe piston Outputs rotary motion to be used to Outputs rotary motion to be used to

do work (ie. Turn pulleys, blades, do work (ie. Turn pulleys, blades, etc.)etc.)

Cylinder BlockCylinder Block

The bore in which the piston ridesThe bore in which the piston rides Usually made into the crankcaseUsually made into the crankcase Generally the largest engine Generally the largest engine

componentcomponent

Cylinder HeadCylinder Head

Detachable portion of the engine that Detachable portion of the engine that houses the combustion chamberhouses the combustion chamber

Can house valve components (OHV Can house valve components (OHV engines)engines)

Always houses spark plug(s)Always houses spark plug(s)

Exhaust ValveExhaust Valve

Valve that permits exhaust to leave Valve that permits exhaust to leave combustion chamber on exhaust combustion chamber on exhaust strokestroke

Always the smaller of the two valves Always the smaller of the two valves (int, ex)(int, ex)

Intake ValveIntake Valve

Valve that permits air/fuel mixture to Valve that permits air/fuel mixture to enter the combustion chamber on enter the combustion chamber on intake stroke intake stroke

Always the larger of the two valves Always the larger of the two valves (int.,ex)(int.,ex)

PistonPiston

Cylindrical part with closed surface Cylindrical part with closed surface area on one end connected to the area on one end connected to the crankshaft via the connecting rodcrankshaft via the connecting rod

Forces fuel/air mixture into Forces fuel/air mixture into combustion chamber combustion chamber

Exerts force back down to the Exerts force back down to the crankshaft crankshaft

Piston HeadPiston Head

Part of the piston above the rings Part of the piston above the rings Can be flat , domed , or dishedCan be flat , domed , or dished

Piston RingsPiston Rings

Expanding rings placed in the Expanding rings placed in the grooves of pistons to create a seal grooves of pistons to create a seal that keeps oil down and the fuel/air that keeps oil down and the fuel/air mixture upmixture up

Never align the open ends when Never align the open ends when installing ringsinstalling rings

Ring types- compression & Ring types- compression &

oiloil

FlywheelFlywheel

Wheel bolted to one end of the Wheel bolted to one end of the crankshaft that maintains the speed crankshaft that maintains the speed of the engine during operationof the engine during operation

Sometimes used for engine balanceSometimes used for engine balance Either used on work-end of the Either used on work-end of the

crankshaft or the free-endcrankshaft or the free-end

Flywheel KeyFlywheel Key

Used to keep the flywheel in placeUsed to keep the flywheel in place Also used as a breaker point in some Also used as a breaker point in some

ignition systemsignition systems

Oil Filler PlugOil Filler Plug

Used for both filling & checking Used for both filling & checking engine oilengine oil

Always locate this plug before doing Always locate this plug before doing anything to any engineanything to any engine

Service life begins Here!Service life begins Here!