JLG 110HX ANSI Service Manual - Manual (Page 60)

SECTION 2 - PROCEDURES
2-36 – JLG Lift – 3120636
c. Readjust for ambient temperature by rotating the
cover one (1) mark per 5°F from 70°F. Rotate
CCW (lean) if warmer than 70°, CW (rich) if
colder than 70°. (If actual temperature is 80°, set
at 1/32" and rotate two (2) marks CCW [lean]
direction.)
d. Tighten the three cover plate screws and check
for free rotation (no sticking or binding) of the
choke shaft.
Carburetor and Governor Adjustments
1. With the aid of an assistant, start the engine at the
platform console and allow it to come up to operat-
ing temperature with the air cleaner installed. Adjust
carburetor idle screw until engine idles at 1000 RPM.
Shut down engine.
NOTE: Steps 2, 3, and 4 are preliminary settings.
2. With engine shut down, turn ‘low (mid) engine’
adjusting screw CCW to the stop. Do not turn past
stop, as this breaks the pot, disabling the governor.
3. On controller, turn ‘high engine’ (P1) adjusting screw
25-30 turns CCW, then 10 turns CW.
4. On controller, turn ‘gain’ (P2) adjusting screw CCW
to the stop, then CW until screw slot is vertical
(approximately 1/4 turn).
5. On controller, turn ‘droop’ (P3) adjusting screw CCW
to the stop, then CW until screw slot is vertical
(approximately 1/4 turn). No further adjustment
should be necessary to ‘droop’ (P3).
6. With the aid of an assistant at platform control con-
sole, start engine and allow to come up to operating
temperature. Then have assistant depress foot-
switch and place engine speed switch to HIGH
ENGINE.
7. If engine surging occurs at this point, turn ‘gain’ (P2)
adjusting screw CCW until surging ceases. Turn
‘high engine’ (P1) adjusting screw until engine runs
at 3000 RPM. Turning the screw CW increases RPM.
Turning the screw CCW decreases RPM.
8. While your assistant continues to depress the foot-
switch, have them place engine speed switch to
LOW ENGINE. Turn ‘low (mid) engine’ adjusting
screw until engine runs at 1625 RPM. Turning the
screw CW increases RPM. Turning the screw CCW
decreases RPM. Shut down engine.
NOTE: If engine surges under no load and you cannot get
enough response from adjusting ‘gain’ (P2), try
adjusting surge screw on actuator. Loosen surge
screw locknut. Disconnect throttle linkage. Turn
surge screw CW until linkage arm moves. Manually
stroke the linkage fully and allow to return slowly
until it stops. Try to move linkage toward return posi-
tion. If linkage moves, turn surge screw CCW 1/2
turn. Again stroke linkage and allow to return slowly
until it stops. Try to move linkage toward return posi-
tion. If linkage moves, turn surge screw CCW 1/2
turn. Again stroke linkage and allow to return slowly
until it stops. Try to move linkage toward return posi-
tion. If linkage moves, turn surge screw CCW 1/2
turn. Repeat this procedure until linkage does not
move after stroking. This will set buffer spring ten-
sion properly. Reconnect throttle linkage.
9. With engine speed switch set to LOW ENGINE,
when footswitch is depressed, engine should imme-
diately respond. If response times lags, turn ‘gain’
(P2) adjusting screw CW to improve response time.
Turn adjusting screw in small increments only until
response time is correct. Turning adjusting screw
too far CW can cause surging. (See step (7) above.)
2.17 PRESSURE SETTING PROCEDURES
Sequence Pressure (Prior to 1990)
1. Plug pressure gauge into quick-connect on high
drive dump valve. Monitor gauge.
2. On sequence valve, loosen nut at main relief. On
sequence valve 4640535 depress plunger; on
sequence valve 4640580 use an allen wrench to turn
the plunger in. Use plunger to set main relief to 300
psi (21 bar).
3. Loosen nut on sequence cartridge and adjust
sequence pressure to 450 psi (31 bar). Tighten nut.
4. Use plunger to set main relief to 3500 psi (241 bar)
and tighten nut on main relief cartridge.
5. Remove pressure gauge.
MARK