Midterms Flashcards
What is the 4 stroke principle?
Intake Compression Power Exhaust
when do we do a Compression test?
after shutdown, to keep the engine warm for better sealing.
what position should the engine be in a Compression test?
TDC, Compression stroke
when timing or installing magneto what position should it be?
Before TDC, #1 cylinder, Compression Stroke
what are 2 methods we use in starting?
Impulse coupling, shower of sparks
where are shower sparks used?
retard breakers
what are retard breakers for?
reduce/eliminate kickback by delaying the sparks
how many sets of breakers are in a magneto?
2
what are the 2 breakers in a magneto?
Normal/Advance firing breaker & retard breaker
when does the retard breakers become active and how?
delays the spark until closer to TDC to prevent kickback
when you’re doing a compression test and you hear a hissing sound coming from the breather what’s the problem?
Piston rings Piston Cylinder
when you’re doing a compression test and you hear a hissing sound coming from the exhaust what’s the problem?
Exhaust Valve Exhaust Valve seat
types of lifters
hydraulic & solid
which type of lifter would compensate thermal expansion and engine heat?
Hydraulic (zero clearance on the valve tip)
what connects the piston to the crankshaft?
connecting rod (piston moves crankshaft)
what’s the most common type of oil pump?
Constant displacement
what does the oil dilution system do?
adds fuel to the oil on shutdown to keep the oil thin for start up next time
why do we wanna keep the oil thin?
for cold weather
if we don’t have a oil dilution system how do you keep the oil thin?
Pre-heating
what viscosity rating should you use in winter operation?
low viscosity
what viscosity rating should you use in summer operation?
high viscosity
if we use 20W50 what does it mean?
20 = viscosity in cold, W = winter grade, 50 = viscosity in operating temperature
how do we get the oil thicker when its warmer?
add thickening agent
what does it mean if there’s a W in front of the grade?
Ashless-Dispersant Oil
what type of oil do we use in break ins?
Mineral oil
What does a mixture control do?
pilot controls it when density and altitude changes (rich or lean)
where does the discharge nozzle sit inside the carburetor?
narrowest point of the venturi for maximimum restricition or the greatest pressure drop
what does the discharge nozzle provides?
provide us constant fuel flow based on venturi effect and differential pressure
what effect does the discharge nozzle have in idle?
none
how do we control the idle rpm?
by adjusting the adjustment screw for idle stop in the throttle.
how do we compensate for no venturi effect?
idle circuit
WHEN INSTALLING A MAGNETO WHERE WOULD THE POSITION BE?
1 Cylinder, compression stroke, firing position
WHICH POSITION SHOULD THE DOT ON THE PISTON RING BE?
On top
WHICH OIL GRADE IS BEST FOR SUMMER TIME? 80 0R 120?
120
WHICH OIL IS BEST FOR BREAKING TIME?
Mineral oil
WHAT IS THE PURPOSE OF IMPULSE COUPLING?
prevents kickback and delays sparks
WHICH TYPE OF LIFTER COMPENSATES FOR THERMAL EXPANSION?
Hydraulic Lifters
NO MARGIN IN THE VALVE
NOTHING
WHAT’S THE JOB OF THE DISCHARGE NOZZLE IN IDLE POSITION IN REGULAR CARBURETOR?
none
CRITICAL LEANING OF THE MIXTURE RATIOS CAUSED BY SUDDEN OPEN OF THROTTLE IS PREVENTED BY?
Accelerator pump
WHERE IS THE DISCHARGE NOZZLE LOCATED IN A NORMAL CARBURETOR?
Narrowest point of the venturi/greatest restriction of the venturi
WHAT DESCRIBES THE PRESSURE CARBURETOR BEST?
prevents carb icing and discharge nozzle is on top of venturi
WHAT DESCRIBES THE CONTINENTAL FUEL INJECTOR BEST?
distributes fuel individually to each cylinder continous flow system.
INSIDE THE MANIFOLD VALVE WHAT CLOSES THE CUT-OFF VALVE?
Spring pressure
WHAT IS THE MOST LIKELY CAUSE OF SUDDEN RICH RUNNING ENGINE AND FUEL DRAINING OUT OF THE INDUCTION FILTER IN AIRBOX?
Float valve has stuck
WHAT IS THE PURPOSE OF OIL BYPASS VALVE?
to have constant speed all the time
A VERNATHERM VALVE IS A DEVICE IN AN OIL SYSTEM USED TO?
control oil flow through cooler
AN OIL DILUTION SYSTEM ADDS FUEL TO THE OIL SYSTEM TO?
thin oil for cold starting
WHERE DO YOU CHECK THE OIL FILTER ELEMENT FOR METAL PARTICLES WITH A MAGNET?
On the outside surface of paper element
PILOT COMPLAINED OF HESITATING WHEN HE DOES A SUDDEN ACCELERATION, WHAT IS LIKELY THE PROBLEM?
Needle is stuck in closed position
