Mercury 15 EFI FourStroke, Service Manual

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4. Slowly heat the water while observing the thermostat and thermometer.
5. Measure the thermostat opening when the specified water temperature is achieved.
a - Minimum thermostat valve lift
Parameter Specification
Start to open temperature 50–54 °C (122–129 °F)
Full open temperature 60–64 °C (140–147 °F)
Valve lift 4.0 mm (0.157 in.)
Thermostat/Electrical Bracket Installation
The thermostat housing and electrical bracket are secured to the engine with the same screws.
1. Install the thermostat into the engine block.
2. Ensure that the mating surfaces on the engine block and the thermostat housing are clean.
3. Thread a new cable tie through the two holes in the electrical bracket.
4. Attach the gasket, thermostat housing, and electrical bracket to the engine block with two screws. Tighten the screws to
the specified torque.
Description Nm lb‑in. lb‑ft
Thermostat housing screws 9.0 79.7 –
5. Use the new cable tie to secure loose wires to the lower end of the electrical bracket.
6. Secure the wires to the upper end of the electrical bracket with the reusable cable tie.
a - Lower cable tie (new)
b - Screw (2)
c - Thermostat housing with new gasket
d - Reusable cable tie
e - Fuse housing
f - Electrical bracket
a
3120
a
b
c
b
d
e
f
63057
Cooling System
90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4D-3