from engine model D333TA in a manner similar to that
3-38.
Overspeed Governor (On Engine Model 687C-
given in (1) above.
18-ES)
b. Cleaning, Inspection and Repair.
a. Removal and Installation.
(1) Clean all parts in an approved cleaning
(1) Disconnect and remove tachometer drive
solvent and dry thoroughly.
cable (fig. 3-70), then tag and disconnect two electrical
leads,
(2) Visually inspect electrical leads for loose
connections or frayed insulation, inspect switch for
(2) Remove four capescrew, lockwasher, and
cracked or dented housing.
flatwashers securing overspeed governor to engine front
cover, then remove governor.
(3) Repair by replacing defective lead or
Switch.
(3) Install in reverie order.
3-87. Low Oil Pressure Switch
b. Cling and Inspection
a. Removal and Installation.
(1) Clean all metal parts with an approved
(1) Refer to figure 3-69, tag and disconnect
cleaning. solvent and dry thoroughly. Wipe microswitch
three electrical leads, then remove low oil pressure switch
with a rag dampened in solvent.
from engine model 687C18ES. Install in reverse order.
(2) Visually inspect mounting hardware and
(2) Remove low oil pressure switch from
other threaded surfaces for burs or stripped threads.
engines model DB83TA in a manner similar to that given
Replace defective parts.
in (1) above.
c. Test for Speed Adjustment.
b. Cleaning, Inspection and Repair.
(1) Start engine (par 2-10).
(1) Clean all parts in an approved cleaning
(2) Run at full throttle. If tachometer indicates
solvent and dry thoroughly.
more than 1,985 15 RPM without shutting down engine,
(2) Visually inspect electrical leads for loose
overspeed governor requires adjustment.
connections or frayed insulation, inspect switch for
(3) If engine shuts down before tachometer
cracked or dented housing.
indicates 1,920 RPM, overspeed governor requires
(3) Repair by replacing defective lead or switch
adjustment
d. Adjustment.
(1) If engine shuts down before tachometer
indicates 1,920 RPM, increase between head of the
adjustment
screw (fig. 3-70) and microswitch arm by
turning adjusting screw counterclockwise then moving
adjusting nut toward throttle lever. Repeat adjustment, by
trial and error, until engine shuts down at 1,985 15
RPM.
(2) If adjustment does not shutdown when
tachometer indicates more than 1,950 RPM, decrease
distance between head of dusting screw and microswitch
arm by backing off adjusting nut, turn adjusting screw
clockwise, then move adjusting nut toward throttle lever.
Repeat adjustment by trial and error until engine shuts
down at 1,985 15 RPKL
(3) Throttle spring tendon is adjusted in a
similar manner by adjustment screw on back side of
overspeed governor. Tighten adjusting screw against
bracket to increase tension screw from bracket to decree
tension.
3-89. Wiring
a. general Crane electrical system consists of wiring
Figure 3-69. Low oil pressure switch removal and
of varied types including harness single including harness,
installation.
single
3-78
