Onan DJA Series User Manual

FLUSH ROCKER BOX OIL LINE
WITH FUEL ANO CLEAN HOLES
WITH FINE WIRE.
FIG. 8-3
BY-PASS VALVE
Located on the outside of the rear bearing plate, the by-pass
valve (Fig. 8-2) controls oil pressure by allowing excess
oil to flow directly back to the crankcase. Normally the valve
begins to open about 25-psi. It is non-adjustable and normally
requires no maintenance.
To determine if high oil pressure is caused by the plunger
sticking closed or low oil pressure by the plunger sticking
open, clean and inspect the valve.
To remove the valve, unscrew the recessed plug in the rear
bearing plate and Uft out the spring and plunger assembly.
Determine proper valve operation by checking the spring and
plunger against the values given below:
Plunger Diameter .3365" to .3380"
Spring -
Free Length 2-5/16 ±1/16"
2.225 lb. . 11 lb. at 1-3/16" (Compressed)
OIL LINES
The rocker box oil Une should be flushed with fuel and
small holes cleaned with fine wire at regular intervals.
Clean out all other oil lines and drillings with compressed
air whenever the engine is disassembled or overhauled.
Reach the oil gage passage by removing the oil filter
mounting plate.
External oil lines, the rocker box oil line and the internal
oil line to the rear bearing are replaceable if damaged.
GAGE
The oil pressure gage is located on the lower front corner
of the cylinder block. Remove it with a wrench and screw in a
new gage if it is faulty. Before replacing, check for clogged
oil passage behind the gage.
OIL PRESSURE SWITCH
The non-adjustable oil pressure switch controls the decom-
pression solenoid in the starting system, allowing it to ener-
gize only when the switch closes. This allows the engine to
build up speed, during starting, before compression occurs.
The switch closes at about 5 psi under increasing oil pres-
sure.
NOTE: This switch is not designed to be used as low oil
oil pressure protection. It won't protect the engine against
slowly decreasing oil pressure.
To check switch operation, if the decompression solenoid
won't energize, short it to ground when the engine has built
up speed during starting. The governor solenoid should ener-
gize immediately and the engine start.
CAUTI ON: When the engine starts, check immediately lor oil
pressure and shut the engine down il oil pressure doesn't
build up within a lew seconds. In. this case it is lack ol oil
pressure that is causing tanlty operation, not fhe switch.
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Onan DJA Series Specifications

General

Brand	Onan
Model	DJA Series
Category	Engine
Language	English