Vacuum Method - MCi MC8 Crusader Maintenance Manual

Crusader
MC-8
MAINTENANCE
[ .,G,_12_- l _O _ _ DATE_J_ul-'---'-y ,_19_7_3 _ ]
MANUAL
position, reset indicator dial to zero, which actually
1s 0.100" on indicator of type registering 0.100" for
ea_ch revolution of indicator needle, then proceed
with valve lever gap adjustments following.
Dial Indicator
...-o.oas"
Valve Assembly
Retained
Horizontally
(Minimum
Range 0.200")
0.085"
t
0.170"
11
A" Le_v~r "C" Lever
Intake Pos,toon
~
t
Exhaust Position
"8" Lever
Center Position
Figure
12-10:
Locating Lever Center
" CORE"
1
MARKS\
R BENDING
1 Ml
,j.,. /
• , @,
SCRI
)F
~
~,,"~,-";~
EXHAU
VALV
LEVER
From Center Position
I· · 0.025' -0.027" Intake
0.035 '.0.037" Exhaust
Figure
12-11:
Adjusting Air Lever
Gap
AIR INTAKE AND EXHAUST VALVE LEVER
ADJUSTING
Before making these adjustments the overtravel
lever must be centered as explained previously.
Two methods of adjustment are available:
(I)
Using both air pressure and vacuum: If vacuum
source is available, this method will take less
time to perform adjustment. Vacuum source is
used to make the exhaust valve lever gap check
only.
(2) Using air pressure only: When this method is
used, it will take longer to perform adjustments
as the valve cover must be in place each time air
pressure is applied and then removed to permit
adjustment of exhaust valve lever.
Instructions covering lever adjustments are iden-
tical for front and rear valves. Rear valve lever and
front valve lever must be bent to proper setting. In
these valves both exhaust and intake levers are part
of one unit which contains "score" marks to permit
easy bending. Personal may accomplish this
operation with lever in the valve body, or lever may
be removed and bent on the bench.
AIR PRESSURE AND
VACUUM METHOD
(I)
Apply available vacuum and regulate air pressure
to approximately 95 P.S.I.
(2) Move overtravel lever fore and aft several times
and then back to center position.
(3) Starting at center position, slowly move lever to
where air intake valve just begins to open. Listen
for escaping air. Note reading on dial at this
point. Reading should be 0.025" to 0.027" from
lever center position. If necessary bend intake
valve lever to correct setting, refer to Figure 12-
1 I.
(4) Return overtravel lever to center position. Slowly
move lever to exhaust side and at the same time
note the vacuum gauge reading. When vacuum
just begins to fall, the exhaust valve has opened.
Valve should open when overtravcl lever is
moved 0.035" to 0.037" from center position. If
necessary, bend exhaust valve lever to correct
setting, refer to Figure 12-1 I.
AIR PRESSURE METHOD
This method may be performed when a vacuum
source is not available.
(I)
Apply air pressure regulated to approximately 95
P.S.I. to air inlet port.
(2) To adjust air intake valve lever gap, move the
overtravel lever slowly from center position to
point where intake valve just begins to open.
Listen for escaping air: Note reading on dial at