Midterms

Question 1

What is the 4 stroke principle?

Answer 1

Intake Compression Power Exhaust

Question 2

when do we do a Compression test?

Answer 2

after shutdown, to keep the engine warm for better sealing.

Question 3

what position should the engine be in a Compression test?

Answer 3

TDC, Compression stroke

Question 4

when timing or installing magneto what position should it be?

Answer 4

Before TDC, #1 cylinder, Compression Stroke

Question 5

what are 2 methods we use in starting?

Answer 5

Impulse coupling, shower of sparks

Question 6

where are shower sparks used?

Answer 6

retard breakers

Question 7

what are retard breakers for?

Answer 7

reduce/eliminate kickback by delaying the sparks

Question 8

how many sets of breakers are in a magneto?

Answer 8

2

Question 9

what are the 2 breakers in a magneto?

Answer 9

Normal/Advance firing breaker & retard breaker

Question 10

when does the retard breakers become active and how?

Answer 10

delays the spark until closer to TDC to prevent kickback

Question 11

when you’re doing a compression test and you hear a hissing sound coming from the breather what’s the problem?

Answer 11

Piston rings Piston Cylinder

Question 12

when you’re doing a compression test and you hear a hissing sound coming from the exhaust what’s the problem?

Answer 12

Exhaust Valve Exhaust Valve seat

Question 13

types of lifters

Answer 13

hydraulic & solid

Question 14

which type of lifter would compensate thermal expansion and engine heat?

Answer 14

Hydraulic (zero clearance on the valve tip)

Question 15

what connects the piston to the crankshaft?

Answer 15

connecting rod (piston moves crankshaft)

Question 16

what’s the most common type of oil pump?

Answer 16

Constant displacement

Question 17

what does the oil dilution system do?

Answer 17

adds fuel to the oil on shutdown to keep the oil thin for start up next time

Question 18

why do we wanna keep the oil thin?

Answer 18

for cold weather

Question 19

if we don’t have a oil dilution system how do you keep the oil thin?

Answer 19

Pre-heating

Question 20

what viscosity rating should you use in winter operation?

Answer 20

low viscosity

Question 21

what viscosity rating should you use in summer operation?

Answer 21

high viscosity

Question 22

if we use 20W50 what does it mean?

Answer 22

20 = viscosity in cold, W = winter grade, 50 = viscosity in operating temperature

Question 23

how do we get the oil thicker when its warmer?

Answer 23

add thickening agent

Question 24

what does it mean if there’s a W in front of the grade?

Answer 24

Ashless-Dispersant Oil

Question 25

what type of oil do we use in break ins?

Answer 25

Mineral oil

Question 26

What does a mixture control do?

Answer 26

pilot controls it when density and altitude changes (rich or lean)

Question 27

where does the discharge nozzle sit inside the carburetor?

Answer 27

narrowest point of the venturi for maximimum restricition or the greatest pressure drop

Question 28

what does the discharge nozzle provides?

Answer 28

provide us constant fuel flow based on venturi effect and differential pressure

Question 29

what effect does the discharge nozzle have in idle?

Answer 29

none

Question 30

how do we control the idle rpm?

Answer 30

by adjusting the adjustment screw for idle stop in the throttle.

Question 31

how do we compensate for no venturi effect?

Answer 31

idle circuit

Question 32

**WHEN INSTALLING A MAGNETO WHERE WOULD THE POSITION BE?**

Answer 32

#1 Cylinder, compression stroke, firing position

Question 33

**WHICH POSITION SHOULD THE DOT ON THE PISTON RING BE?**

Answer 33

On top

Question 34

**WHICH OIL GRADE IS BEST FOR SUMMER TIME? 80 0R 120?**

Answer 34

120

Question 35

**WHICH OIL IS BEST FOR BREAKING TIME?**

Answer 35

Mineral oil

Question 36

**WHAT IS THE PURPOSE OF IMPULSE COUPLING?**

Answer 36

prevents kickback and delays sparks

Question 37

**WHICH TYPE OF LIFTER COMPENSATES FOR THERMAL EXPANSION?**

Answer 37

Hydraulic Lifters

Question 38

**NO MARGIN IN THE VALVE**

Answer 38

NOTHING

Question 39

**WHAT'S THE JOB OF THE DISCHARGE NOZZLE IN IDLE POSITION IN REGULAR CARBURETOR?**

Answer 39

none

Question 40

**CRITICAL LEANING OF THE MIXTURE RATIOS CAUSED BY SUDDEN OPEN OF THROTTLE IS PREVENTED BY?**

Answer 40

Accelerator pump

Question 41

**WHERE IS THE DISCHARGE NOZZLE LOCATED IN A NORMAL CARBURETOR?**

Answer 41

Narrowest point of the venturi/greatest restriction of the venturi

Question 42

**WHAT DESCRIBES THE PRESSURE CARBURETOR BEST?**

Answer 42

prevents carb icing and discharge nozzle is on top of venturi

Question 43

**WHAT DESCRIBES THE CONTINENTAL FUEL INJECTOR BEST?**

Answer 43

distributes fuel individually to each cylinder continous flow system.

Question 44

**INSIDE THE MANIFOLD VALVE WHAT CLOSES THE CUT-OFF VALVE?**

Answer 44

Spring pressure

Question 45

**WHAT IS THE MOST LIKELY CAUSE OF SUDDEN RICH RUNNING ENGINE AND FUEL DRAINING OUT OF THE INDUCTION FILTER IN AIRBOX?**

Answer 45

Float valve has stuck

Question 46

**WHAT IS THE PURPOSE OF OIL BYPASS VALVE?**

Answer 46

to have constant speed all the time

Question 47

**A VERNATHERM VALVE IS A DEVICE IN AN OIL SYSTEM USED TO?**

Answer 47

control oil flow through cooler

Question 48

**AN OIL DILUTION SYSTEM ADDS FUEL TO THE OIL SYSTEM TO?**

Answer 48

thin oil for cold starting

Question 49

**WHERE DO YOU CHECK THE OIL FILTER ELEMENT FOR METAL PARTICLES WITH A MAGNET?**

Answer 49

On the outside surface of paper element

Question 50

**PILOT COMPLAINED OF HESITATING WHEN HE DOES A SUDDEN ACCELERATION, WHAT IS LIKELY THE PROBLEM?**

Answer 50

Needle is stuck in closed position