JLG 660SJ ANSI Service Manual - Manual (Page 110)

SECTION 3 - CHASSIS & TURNTABLE
3-56 – JLG Lift – 3120718
Examine the system for springs, such as carburetor return
springs. These should be removed. Some automotive car-
buretors (as opposed to industrial carburetors) contain
internal springs for accelerator pumps, etc. These may
make good governing difficult, or even impossible. For
this, and other reasons, industrial carburetors are much to
be preferred.
Move the linkage slowly through its travel, and look for
any binding or unexplained forces. Correct any before
going further.
Many “governing” problems are really caused by binding
of the butterfly and its shaft in the carburetor. This is
caused by loading due to vacuum under the butterfly and
atmospheric pressure above when the engine is running.
These forces cannot be felt when the engine is not run-
ning. Therefore, start the engine while carefully controlling
the speed by hand, and feel for binding or airload forces.
Needle bearings on the butterfly shaft are available on
many industrial carburetors to deal with this problem. Any
tendency on the butterfly stick must be corrected.
Mounting-Controller
Select a reasonably cool, dry, and vibration free location.
The rear cover will probably need to be removed during
set-up in order to make adjustments for speed setting and
gain. You may wish to defer final installation until this is
done.
After completing these adjustments, replace cover. Mount
so that water cannot pool on this cover. Always mount the
controller with the strain relief down. This will prevent
water from entering thru the cable, also place the vent
hole in the bottom of the controller down.
Wiring
See wiring diagram for details of hook-up.
Use #16 wire minimum.
Keep all wiring to the Governor as short as is practical.
Go directly from the controller ground terminal (B of the 8
pin connector) by dedicated wire, to the battery “minus”
terminal. If this cannot be done, for some reason, go by
dedicated wire to a very good engine ground.
A properly functioning engine electrical system will supply
13.5 - 14.8 VDC when the engine is running. If wiring size
is adequate, with good connections and proper grounds,
you will get this reading between the wires terminals A & B
of the 8 pin connector when the Governor is controlling
engine speed. Verify this.
Improper hook-up can damage electronics. Re-check wir-
ing before applying power.
Check-Out and Initial Start-Up Procedures
Before proceeding, familiarize yourself with the locations
of the various adjustment pots. There are two types of
adjustment pots.
Multi-Turn Adjustment (High Engine, Mid
Engine, Overspeed, Starter Lockout)
This adjustment is made by turning the 1/8" brass screw
clockwise (CW) to increase speed, and counterclockwise
(CCW) to decrease speed. The adjustment range of the
pot is 25 turns, and one full turn will change speed about
100-200 rpm. This pot is protected by a slip clutch at each
end, and will not be harmed by moderate over-adjust-
ment. However, the Governor will not function while the
pot is past full travel. If you suspect you may have over-
adjusted the High Engine pot, or have lost track of where
you are, turn the pot 25-30 turns CCW, then back 10-12
turns CW to get back into the range of normal adjustment.
Single-Turn Adjustment (Gain, Factory
Adjust)
This pot is 3/8" square and has a 1/8" plastic screw in its
center. Be gentle! This pot turns 270 degrees, and over-
turning will break the internal stops, making adjustment
impossible. Turning this pot CW increase Governor sensi-
tivity. On most applications, best operation is achieved
with the pot set as shown in diagram below.
NOTE: These settings are factory set, Start Lockout, Fac-
tory Adjust and Overspeed. They are conformally
coated by P.G. and should not need to be reset.
Assuming that the Actuator and Controller are mounted,
the wiring is run and checked, and that the linkage is
properly installed, proceed as follows:
1. Turn ignition switch on. Do not start engine. Actuator
should kick toward max. fuel once, and then imme-
diately return to min. fuel. If not, see Troubleshoot-
ing.
2. Use multimeter to check battery voltage at battery
terminals, and record. Now check voltage at the
machine connection points for terminals A & B of the
8 pin connector on the E-331 (A is +, B is -). Voltage
reading should be the same as at battery. If not, shut
down, and correct wiring.
3. Hold the linkage back by hand, so as to control
engine speed manually. Start engine, set vehicle
controls to obtain High Engine speed, gradually
release the linkage, and adjust the speed-set as
needed to set the speed as desired. If engine speed
surges, reduce Gain a little, as required (CCW).