Page 233 - REPOWER REFERENCE GUIDE (2020)

Single Catalyst V8 Engines
51 mm (2 in.) Riser Kit for Emissions Control Exhaust Manifolds (P/N 8M0104209)

Qty. Description Part Number
1 Exhaust elbow, port, 51 mm (2 in.) NSS
1 Exhaust elbow, starboard, 51 mm (2 in.) NSS
2 Elbow‑to‑manifold gasket (seawater cooled) 27‑8M2004414
2 Elbow‑to‑manifold gasket (closed‑cooling) 27‑8M2004606
2 Pipe plug (3/4 x 14 socket head) 22‑428611

102 mm (4 in.) Riser Kit for Emissions Control Exhaust Manifolds (P/N 8M0104210)

Qty. Description Part Number
1 Exhaust elbow, port, 102 mm (4 in.) NSS
1 Exhaust elbow, starboard, 102 mm (4 in.) NSS
2 Elbow‑to‑manifold gasket (seawater cooled) 27‑8M2004414
2 Elbow‑to‑manifold gasket (closed‑cooling) 27‑8M2004606
2 Pipe plug (3/4 x 14 socket head) 22‑428611

152 mm (6 in.) Riser Kit for Emissions Control Exhaust Manifolds (P/N 8M0104211)

Qty. Description Part Number
2 Exhaust elbow, 152 mm (6 in.) NSS
2 Elbow‑to‑manifold gasket (seawater cooled) 27‑8M2004414
2 Elbow‑to‑manifold gasket (closed‑cooling) 27‑8M2004606
2 Pipe plug (3/4 x 14 socket head) 22‑428611
2 Check ball fitting assembly (90°) 8M2012292
Exhaust Elbow Removal

1. Turn the engine off and allow it to cool.
! 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.

2. Disconnect the battery cables from the battery. Be certain to remove the negative (–) cable first.
3. Disconnect the oxygen sensor and the exhaust manifold coolant temperature sensor from the harness.
4. Drain the engine coolant:
• On seawater‑cooled models, drain the seawater section of the engine. Refer to Section 1C.
• On models with closed cooling, drain the coolant until the level is below the exhaust elbow joint area. Refer to the
Draining procedure in Section 6C.
• Note the locations and connections of the hoses for reassembly.
5. Disconnect the engine exhaust hoses. Retain the hose clamps.
6. Remove and retain the four fasteners securing the exhaust elbow to the manifold.
IMPORTANT: Remove the exhaust elbow carefully to ensure that the catalyst does not fall from the manifold.
7. Remove the exhaust elbow.
NOTICE
Exposing the catalyst to foreign materials such as silicone, oils, or fiberglass can chemically alter the precious metal coating
of the catalyst and compromise its ability to convert exhaust gases. Handle catalyst components in a clean environment only.

90-8M0149179 eng NOVEMBER 2018 © 2019 Mercury Marine Page 7E-17