18020 Mercruiser STUD, FLAME ARRESTOR - NEW DESIGN

Note: Plug or cap all open ports with new plugs or caps.
Illustration 1 g02177350
Drain the coolant from the cooling system into a suitable container for storage or disposal. Refer to Operation and Maintenance Manual, "Cooling System Coolant - Change" for the correct procedure.
Loosen bolts (1) for the support bracket.
Remove bolt (2) from clip for tube assembly.
Remove bolts (3) and bolts (11). Remove tube assembly (5) from the exhaust cooler and induction mixer.
Remove gasket (4) (not shown) and gasket (12) (not shown).
Remove bolts (7) and bolts (10). Remove tube assembly (6) from the exhaust cooler and from the cylinder head.
Remove gasket (8) (not shown) and gasket (9) (not shown).
Illustration 2 g02177373
Cut cable straps (16).
Remove bolts (14) and bolts (18) from tube assembly (15). Remove the tube assembly (15) from the exhaust cooler.
Remove gasket (13) (not shown) and gasket (17) (not shown).
Illustration 3 g03423064
Illustration 4 g02367616
Remove bolts (24) and bolts (26) from tube assembly (25).
Loosen bolts (20) in reverse numerical order. Refer to Illustration 3.Note: Loosening the bolts in reverse numerical order will help prevent distortion of the exhaust manifold.
Remove bolts (20) and the spacers from exhaust manifold (19).Note: Support the manifold as the bolts are removed.
Remove exhaust manifold (19).
Remove exhaust manifold gaskets (21) (not shown) and exhaust manifold gaskets (22) (not shown).
Remove tube assembly (25). Remove gasket (23) (not shown) and gasket (27) (not shown).Installation Procedure
Table 1
Required Tools
Tool Part Number Part Description Qty
B(1) 366-1820 Manifold Alignment Pins 2
C(2) 366-1819 Manifold Alignment Pins 2
(1) Tooling (B) is used to hold the gasket in position and align the exhaust manifold.
(2) Tooling (C) is used to align the exhaust manifold.
Ensure that wiring harness are correctly routed and the cable straps are not over tightened. Over tightening of the cable straps will damage the wiring harness convoluting.
Illustration 5 g03423065
Illustration 6 g02367616
Ensure that exhaust manifold (19) is clean and free from damage. If necessary, replace the exhaust manifold. Clean the gasket surface of the cylinder head.
Position a new exhaust manifold gasket (21) (not shown) onto the cylinder head. Install Tooling (B) in Position (X). Install Tooling (C) in Position (Y). Refer to Illustration 5.Note: Ensure that the exhaust manifold gasket is correctly oriented.
Position a new exhaust manifold gasket (22) (not shown) onto the cylinder head. Install Tooling (B) in Position (X). Install Tooling (C) in Position (Y). Refer to Illustration 5.Note: Ensure that the exhaust manifold gaskets are correctly oriented.
Position a new gasket (27) (not shown) onto a new tube assembly (25). Position tube assembly onto the NRS exhaust cooler and install new bolts (26) and tighten the bolts ensuring that the tube assembly can still move.
Position a new gasket (23) (not shown) onto tube assembly (25)
Align exhaust manifold (19) with Tooling (A). Install the exhaust manifold to the cylinder head.
Install bolts (24) for tube assembly (25) and tighten the bolts ensuring that the tube assembly can still move.
Install new bolts (20) and the spacers in the eight available position to exhaust manifold (19).
Tighten bolts (20) one to four to a torque of 44 N m (32 lb ft). Tighten the bolts in the sequence that is shown in Illustration 5.
Remove Tooling (A). Install remaining new bolts (20) and the spacers to exhaust manifold (19).
Tighten remaining bolts (20) to a torque of 44 N m (32 lb ft). Tighten the bolts in the sequence that is shown in Illustration 5.
Tighten bolts (24) and bolts (26) for tube assembly (25) to a torque of 22 N m (195 lb in).
Illustration 7 g02177373
Position a new gasket (13) (not shown) and a new gasket (17) (not shown) onto tube assembly (15).
Position tube assembly (15) onto the exhaust cooler and the cylinder head.
Install bolts (14) and bolts (18). Tighten bolts hand tight.
Tighten bolts (14) to a torque of