Yanmar 3YM20 Operation Manual page 42

4. MAINTENANCE AND INSPECTION
1. Check the fuel level in the fuel tank.
Replenish if Insufficient
2. Loosen the air bleeding bolt at the top
of the fuel filter by turning it 2 or 3
times.
3. Feed fuel with the fuel feed pump by
moving the lever on the left side of the
feed pump up and down.
4. Allow the fuel containing air bubbles to
flow out from the air bleeding bolt hole.
When the fuel no longer contains bub-
bles, tighten the air bleeding bolt. This
completes the air bleeding of the fuel
system.
5. After the engine start-up, the automat-
ic air-bleeding device works to purge
the air in the fuel system. No manual
air-venting is required for normal en-
gine operation.
EN
C
E
F
G
A Cylinder head
B Bracket
C Fuel pipe
D Fuel filter
(2) Drain the fuel/water separator (op-
tional).
1. Close the fuel cock of the fuel tank.
42
A
B
D
E Fuel injection pump
F Clamp
G Fuel pipe
2. 2.Loosen the drain plug and drain off
any water and dirt collected inside.
Note: If no drain drips when the drain plug is
opened, loosen the air bleeding plug on the
top of the fuel/water separator by turning
counter-clockwise 2-3 times. (This may oc-
cur if the position of the fuel/water separator
position is higher than the fuel oil level in the
fuel tank).
3. After draining, be sure to tighten the
air bleeding plug.
4. Be sure to bleed air in the fuel system.
(3) Check the Electrolyte Level in a
Battery
WARNING
Before inspecting the electrical
system, be sure either to turn off
the battery switch or to disconnect
the (-) terminal of the ground cable.
Otherwise, a short-circuit could
cause a fire.
Ensure good ventilation when
charging the battery. The use of
open flames is strictly prohibited.
Hydrogen gas may also catch fire.
Battery fluid is dilute sulphuric ac-
id. It can blind you or burn your
eyes or skin. Wear goggles and
gloves when handling battery fluid.
Should the fluid be deposited on
your skin, wash with a large quanti-
ty of fresh water and seek treatment
from a doctor.
1. If operation continues with insufficient
battery fluid, the battery will be de-
stroyed.
Check the fluid level periodically. If the
level is lower than specified, fill with
distilled water (available in the market)
up to the upper limit of the battery.