3-1. ENGINE MAINTENANCE (CONT)
a. Engine Tune-up (SHEET 12 OF 21).
(6) Engine Compression Check (Cont).
If compression of each cylinder is equal to or greater than listed com-
pression, go to step (1) below. If compression of one or more cylinders
is less than listed compression, troubleshoot engine (page 2-43).
(1) Identify and compare highest and lowest recorded compression values.
Difference between two or more cylinder compression values should be no
more than 25 psig.
If difference between highest and lowest cylinder compression values is
no more than 25 psig, go to step (m) below. If difference between two or
more compression values is more than 25 psig, troubleshoot engine (page
(m) Test fuel injector nozzles (page 3-110).
(n) Install fuel injector nozzles (page 3-113).
(7) Fuel Injection Governor Adjustments.
(a) No-Load Governed Speed Adjustment.
Start engine and operate at
1200 rpm to reach normal
Tell assistant to press ac-
celerator pedal fully, and
press tachometer against en-
gine tachometer drive shaft.
When tachometer pointer stops
moving, record tachometer in-
dication. Engine no-load gov-
erned speed should be 2300 to
Tachometer drive shaft operates at half engine speed. Double tachometer
indication to obtain engine rpm.
If tachometer does not indicate specified no-load governed speed with
engine at normal operating temperature, perform the following steps to
adjust engine speed.