Chapter 14

True or False. an outside micrometer can be used to measure the thickness of a valve stem

False

True or False. the camshaft is responsible for opening the valves

True

True or False. the choke is responsible for variant the percentage of air in the fuel-air mixture that enters the cylinder

True

what are the two strokes commonly associated with a two-stroke cycle engine?

compression and Power

A comparison of the volume in the cylinder with the piston at the bottom dead center versus top dead center is known as the

compression ratio

When starting a cold engine, a ____ fuel-air mixture is desirable

rich

identify three things that the flywheel is responsible for in a small gas engine

1) used to store energy provided by power stroke in form of inertion 2) help the engine Coast through exhaust, intake, and compression 3) smooth out the power produced by the engine for the engine does not appear to constantly slow down and speed up

2 advantages of four-stroke cycle engine

1)exhaust of two-stroke cycle engine is dirtier than a 4-stroke 2) every other stroke is a power stroke which makes two stroke cycle engines wear more rapidly than four stroke

4-stroke cycle process

1)intake stroke- downward stroke of the Piston that begins process of producing power 2)compression power- upward movement of piston and connecting rod assembly 3)Power stroke- stroke in which power is transferred from piston to the connecting rod and then to the crankshaft 4) exhaust stroke- final movement in the cycle-upward stroke of piston

describe four things that oils does besides provide lubrication

1)protect internal engine parts from corrosion 2) improve fuel economy 3) seal the engine by filling small space between moving Parts such as piston rings and cylinder wall 4) Christian moving engine parts from the tremendous force of power stroke on combustion

one complex revolution of the crankshaft will produce a power stroke in an

2 stroke cycle engine

list four critical areas within an engine

Cam lobes Intake and exhaust valves camshaft front and rear bearings camshaft front and rear journals

if your small gas engine will not start, and you know it has fuel, a logical troubleshooting step would be to

check for spark

Identify six causes of malfunctions in an engine

engine overchoked water in fuel no fuel in tank poor compression loose flywheel worn cylinder

Heat is generated outside the cylinder in an ____ combustion engine

external

true or false. ignition occurs before the piston reaches top dead center is the intake stroke

false

An ______ attached to the connecting rod provides splash lubrication for many small gas engines

oil dipper