Northern Lights M65C13, Operator'S Manual

Page: 37 / 122

Lubrication & Maintenance/250 Hour/6 Month
RG19661,00003D5 -19-29JAN13-1/2
RG19661,00003D5 -19-29JAN13-2/2
Inspect and Replacing Zinc Plugs
Two zinc plugs (A) are installed in the sea water cooling
system to help reduce the corrosive action of salt in the
sea water. The reaction of the zinc to sea water causes
the plugs to deteriorate, instead of the more critical
cooling system parts. Therefore, the zinc plugs MUST BE
inspected every 250 Hours.
NOTE: Zinc plugs are located in each heat exchanger end
cap and are mounted on hex-head pipe plug.
1. Remove zinc rod from each end cap (B) and observe
condition of each.
2. Tap the zinc rods lightly with a hammer. If rod flakes
apart when tapped, install a new zinc plug.
A—Zinc Plugs B—End Cap
RG22137
—UN—06DEC12
Inspect Zinc Plugs - 4 Cylinder
RG22048
—UN—29NOV12
Inspect Zinc Plugs - 6 Cylinder
3. Measure zinc plugs (A) to determine the amount of
erosion on length (B) and outer diameter (C).
If length is less than 15.9 mm (0.63 in.) or outer diameter
is less than 4.8 mm (0.19 in.) on either plug, replace all
zinc plugs.
NOTE: Zinc plug new part dimensions are 31.8 mm (1.25
in.) long and 9.5 mm (0.38 in.) outer diameter.
A—Measure Zinc Plugs
B—Measure Length C—Measure Diameter
RG6007
—UN—27JAN92
Zinc Plug Erosion
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