4 - Stroke Engine

Which stroke is designated by the piston moving from TDC to BDC with both the intake and exhaust valves in the closed position? 

• Intake 
• Compression 
• Power 
• Exhaust 

A four - stroke engine generates power _____ time(s) during a complete cycle. 

• 1
• 2
• 3
• 4

During the intake stroke, ________________________________. 

• Spent gases are forced out of the combustion chamber from the piston's travel from BDC to TDC
• Fuel is supplied to the combustion chamber
• The piston travels from BDC to TDC to compress the fuel charge prior to ignition
• Air - fuel mixture is deposited into the combustion chamber

Spark is a necessary element of internal combustion engine operation. How do small 4-stroke engines create spark to ignite the charge in the combustion chamber? 

• The upward force of the piston provides the spark needed to ignite the charge.
• Friction between the ignition armature and the magneto creates an electric arc that sends high voltage to the spark plug. 
• Fuel in the carburetor is vaporized by high speed air injected from the choke side of the carburetor.
• None of the above

List the strokes of the 4 - cycle engine theory in order. 

• Intake, Power, Compression, Exhaust 
• Intake, Compression, Power, Exhaust 
• Exhaust, Power, Compression, Intake 
• Compression, Power, Intake, Exhaust 

Piston force and subsequent motion are transferred to the crankshaft on which of the following engine strokes? 

• Intake 
• Compression
• Power 
• Exhaust 

Compression is best defined as ___________________________. 

• Expanding a small volume into a larger volume 
• Reducing a larger volume into a smaller volume 

Ignition of the charge occurs in between the following two strokes: _________________ and _________________. 

• Intake, Power, 
• Power, Exhaust 
• Compression, Power 
• Intake, Compression 

The crankshaft is able to continue rotating after the power stroke has completed as a result of inertia created by the _____________________. 

• Flywheel 
• Blower Shroud 
• Magneto 
• Rewind Starter 

Valve overlap is best defined as _____________________________. 

• a)  The period during engine operation when both intake and exhaust valves are open at the same time near in between the exhaust and intake strokes
• a)  The period during engine operation when both intake and exhaust valves are open at the same time near in between the intake and compression strokes. 
• a)  Grinding of the valve seat to produce a beveled angle of 30 to 45 degrees. 
• None of the above