Mercury 25 EFI FourStroke User Manual page 154

Dual Outboards
Connect a common ground cable (wire size same as engine
battery cables) between negative (–) terminals on starting
batteries.
b
c
a - Red sleeve ‑ positive (+)
b - Black sleeve ‑ negative (–)
c - Ground cable
d - Cranking battery
FUEL TANKS
Portable Fuel Tank
Select a suitable location in the boat within the engine fuel line
length limitations and secure the tank in place.
Permanent Fuel Tank
Permanent fuel tanks should be installed in accordance with
industry and federal safety standards, which include
recommendations applicable to grounding, anti‑siphon
protection, ventilation, etc.
INSTALLATION
b
a
(-)
a
(-)
d
144
d
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eng