Indmar 5.7L Vortec Operator's Manual page 62

assemblies.
Fresh Water Cooling – All Systems
All fresh water cooling systems, whether they are half or
full systems, must be inspected and maintained annually,
usually during winterization.
Heat Exchanger – Remove the end caps to drain and
inspect the heat exchanger. Clean out any debris. Make
sure you inspect the end caps for contour and cracks
and replace the neoprene gaskets before putting the
boat back in service. If you find rubber bits in the
exchanger, check the raw
water pump impeller. Note
that if you use a clean-out
rod, it should be softer than
the copper tubes, and
should not be used to dis-
lodge materials which are
firmly stuck to the tube sur-
face, as this could damage
the tubes. The rod will
assist in cleaning out bits of
grass, zinc, shells, and
similar materials which are
just lodged in the tubes.
6-12
SACRIFICIAL ANODE
REPLACE IF ANODE HAS
REDUCED TO 1/2 OF
ORIGINAL SIZE
INDM-B007
Figure 6.7 – Sacrificial
Anode
Zinc Anodes – The sacrificial zinc anodes frequently
spall, and there will probably be zinc bits in the exchang-
er which should be cleaned out. Inspect the zinc anode
often during use and replace when half gone.
Raw Water Pump – Replace the impeller if it is worn or
over two years old. Since you must remove the impeller
to inspect it, it is good practice to replace the impeller
every year as a routine. Be sure there are no impeller
parts lodged in the hoses or elsewhere in the system as
they will eventually move to an inconvenient place and
restrict water flow. The raw water pump impeller should
be replaced every two years or whenever it is found
to be worn or have damaged blades. Be sure to
re-assemble with the proper gaskets.
Figure 6.8 – Raw Water Pump Impeller
INDM-A036
Indmar Marine Engines