Yanmar 3JH4E Service Manual page 50

2. Inspection and Adjustment
b) Spray and injection states
• Operate the nozzle tester lever at a rate of once
or twice a second and check no abnormal
injection.
• If normal injection as shown below cannot be
obtained, replace the fuel injection valve.
• No extreme difference in angle(
• No extreme injection angle difference(
• Finely atomized spray
• Excellent spray departure
3) Nozzle valve sliding test
Wash the nozzle valve in clean fuel oil. Place the
nozzle body vertically and insert the nozzle into the
body to about 1/3 of its length. The valve is normal
if it smoothly falls by its own weight into the body.
In case of a new nozzle, remove the seal peel, and
immerse it in clean diesel oil or the like to clean the
inner and outer surfaces and to thoroughly remove
rust-preventive oil before using the nozzle. Note
that a new nozzle is coated with rust-preventive oil
and is pasted with the seal peel to shut off outer
air.
4) Nozzle punch mark
(3) Check the impeller of the cooling water pump(seawater pump)
The impeller must be replaced with new one periodically (every 1000 hrs or four years whichever comes
first).
Refer to 2.2.4 (5) for the procedure.
Θ
)
α
)
(Nozzle valve sliding check by gravity)
34
Abnormal
Extreme difference in angle ( )
Extremely different injection angle ( )
Non-atomized spray
Stagnant spray
A 159 P 18 5 VAD1
Injection angle
Nozzle insertion angle
CodeA: angled
No code: no angle
Punch mark
Design code
Number of hole
(5 holes)
Diameter of hole
( 0.18)
Size: sizeP
sizeS
YANMAR