Yanmar 6LY3 series Service Manual page 208

COOLANT SYSTEM
Positioning the Strainer
1. Attach the strainer in the lowest position of the
bilge about 20 mm (0.8 in.) above any sludge.
2. Attach the strainer with a 1.2 to 1.8 m (4 to 6 ft)
length of hose and allow plenty of slack.
3. Secure the strainer so that it will not turn upside
down or on its side. Use the supplied hose and
avoid thin vinyl hose and hose that is not heat
resistant.
4. Check the strainer operation before tightening
its mounting hardware. (Avoid damaging the
hull.)
5. The strainer contains a weight and can be used
with the weight in place.
6. Always keep the strainer clean.
Attaching the Bilge Pump Outlet Nozzle
1. Install the outlet nozzle on the discharge side of
the pump.
2. Make a hole of 21 mm (0.8 in.) or less for
attaching the nozzle. The hose attached at the
nozzle should be 1.8 m (6 ft) or less and should
connect without strain.
Attaching the Hoses
1. Use a regulation hose. NEVER use a thin vinyl
hose or a non-heat resistant hose. Attach the
hose from the strainer to the pump inlet. Make
the hose as short as possible and avoid sharp
bends.
2. Attach the delivery nozzle hose to the nozzle
outlet.
Testing the Bilge Pump
1. Check for any problems with the hose or wiring.
Then, connect the battery.
2. Add water to the bilge.
3. Turn the pump switch to ON. Verify that the
water is drawn in and discharged properly. The
pump will stop automatically when there is no
water left.
4. If the pump cavitates for more than 10 seconds,
lift the strainer above the water level and stop
the pump. Prime the pump before running it
again.
7-22
Bilge Pump and Strainer Components and Functions (Optional)
© 2007 Yanmar Marine International
Installing the Strainer
After testing the bilge pump, install the strainer in
place with bolts. (Avoid damaging the hull.)
Replacing the Bilge Pump Impeller
NOTICE: The bilge pump impeller should be
replaced by an authorized YANMAR service center.
"Bolt Lock" is applied to the threads of the impeller
plate mounting bolts. Use a hair dryer to soften the
lock on the threads.
1. Remove the four M4 bolts that secure the
impeller plate on top of the diaphragm switch.
2. Clean the impeller, the impeller cavity and the
impeller plate.
3. Apply a light coat of grease to the impeller, the
plate and the side-gap adjusting shim(s).
4. Insert the shim(s) first and then the impeller.
5. Install the impeller plate.
Adjusting the Bilge Pump Impeller Side Gap
The impeller replacement kit includes one impeller
and three shims for adjusting the impeller side gap.
If the bilge pump has no output after replacing the
pump impeller, shim the impeller to obtain the
specified pump characteristics.
Ensure that the pump is performing to capacity by
checking the current flow during operation. Select a
shim combination that provides for a 10A current
draw at 12VDC or a 5A current draw at 24VDC.
NOTICE: If too many shims are used, the electric
current will be too great and will blow a fuse.
6LY3 Service Manual