Page 235 - REPOWER REFERENCE GUIDE (2020)

Single Catalyst V8 Engines
5. Tighten the fasteners to the specified torque in the sequence shown below:

3 1

2 4

50084
Elbow shown with components removed for clarity

Description Nm lb‑in. lb‑ft
Fasteners 49 – 36.1
6. Connect the oxygen sensor and the exhaust manifold coolant temperature sensor to the harness.
7. Connect the water hoses in the same location they were removed:
a. On seawater‑cooled models, connect the engine water hoses to the exhaust elbows and tighten the hose clamps.
b. On models with closed‑cooling:
i. Connect the elbow drain hose from the Y‑fitting to the fitting assembly and tighten the hose clamps to the
specified torque.
ii. Connect the engine water hose from the heat exchanger to the exhaust elbow and tighten the hose clamps to the
specified torque.
Description Nm lb‑in. lb‑ft
Hose clamps 3 26.6 –
8. Connect the engine exhaust hoses, using two hose clamps at each connection. Tighten the clamps to the specified torque.
Description Nm lb‑in. lb‑ft
Hose clamps 3 26.6 –
9. Fill the closed‑cooling system, if equipped, with the recommended antifreeze.
10. Connect both battery cables to the battery, being certain to connect the negative cable last.
11. Upon starting the engine, inspect all exhaust and cooling hose connections for leaks.
Exhaust Manifolds

Exhaust Manifold Removal

! WARNING

Performing service or maintenance without first disconnecting the battery can cause product damage, personal injury, or
death due to fire, explosion, electrical shock, or unexpected engine starting. Always disconnect the battery cables from the
battery before maintaining, servicing, installing, or removing engine or drive components.

1. Disconnect both battery cables from the battery. Be certain to disconnect the negative (–) cable first.
2. On sterndrive models:

90-8M0149179 eng NOVEMBER 2018 © 2019 Mercury Marine Page 7E-19