2-28.
In a two-stroke cycle engine with
aluminum pistons, what is the
maximum wear limit for the liner?
1.
0.0015 in. per inch diameter
2.
0.0025 in. per inch diameter
3.
0.0030 in. per inch diameter
4.
0.0050 in. per inch diameter
2-29.
Which of the following conditions
will NOT cause cracks on an engine
cylinder head?
1.
Obstruction in the combustion
space
2.
Restriction of cooling passage
3.
Addition of hot water to a
cold enqine
4.
Improperly tightened studs
2-30.
What valve casualty is usually
caused by resinous deposits left
by improper lube oil or fuel?
1.
Burned valves
2.
Sticking valves
3.
Weak springs
4.
Bent valves
2-31.
After inspecting the engine intake
valves, you discovered that the
surface of the valve head has
damage.
Which of the following
casualties is the most probable
cause?
1.
It is sticking
2.
It has a weak spring
3.
It is bent
4.
It has a loose valve seat
2-32.
Which of the following valve
casualties will cause the valve to
fail to close completely?
1.
A burned valve
2.
A valve float
3.
A sticking valve
4.
A valve that has a weak spring
2-33.
Failure to properly prepare the
counterbore area before placing a
valve seat insert in it will cause
what problem?
1.
Uneven heat transfer between
the seat and the counterbore
2.
Scratching of the insert
3.
Misalignment of the valve head
in the seat
4.
Loose fit of the insert in the
counterbore
2-34.
When replacing a valve seat
insert, which of the following
procedures should you follow?
1.
Plan the operation so that the
insert is placed slowly and
precisely
2.
Use boiling water to heat the
valve seat
3.
Drive the insert down with a
special tool
4.
Shrink the valve guides or
counterbore with dry ice
2-35.
Minor pits and flaws may be
removed from the valve seat by
what method?
1.
Buffing
2.
Hand grinding
3.
Insert replacement
4.
Rubbing with prussian blue
2-36.
How are valves refaced?
1.
On a lathe
2.
Against the valve seat
3.
By machine qrinding
4.
Each of the above
2-37.
Which of the following conditions
will cause valve springs to break?
1.
Compression and corrosion
2.
Misalignment and compression
3.
Corrosion and fatique
4.
Fatique and compression
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