42985 Mercury STUD, CARBURETOR

2. Remove sensor (7) from cylinder head (8). If necessary, remove the O-ring seal from sensor (7).3. Remove bolt and locknut (5).4. Disconnect connector (6).5. Remove bolt (4) and sensor (3). If necessary, remove the O-ring seal from sensor (3).6. Remove three bolts (2) and water lines group (1). 7. Remove bolt (9) from timing advance housing.8. Remove bolt (10) and support (11). 9. Remove the bolt and support (12). Remove the remaining ten bolts and the supports along the intake side of the cylinder head.10. Disconnect hose clamp (13) from the exhaust manifold. 11. Attach Tool (A) and fasten a hoist.12. Remove bolts (14) and the cylinder head. The weight of the 3408 cylinder head is approximately 90 kg (198 lb). The weight of the 3412 cylinder head is approximately 172 kg (380 lb).
Do not put the cylinder head down on a flat surface. Direct injection nozzles extend out from the bottom surface of the cylinder head and will be damaged by the weight of the head.
Install Cylinder Head
1. Thoroughly clean the bottom surface of the cylinder head. Install a new head gasket and water seals. Do not use any adhesives. A new spacer plate gasket must be used when the cylinder head is installed. See the topic "Remove & Install Spacer Plate" in this module. 2. Attach Tool (D)and fasten a hoist.3. Install the cylinder head to the block. The weight of the 3408 cylinder head is approximately 90 kg (198 lb). The weight of the 3412 cylinder head is approximately 172 kg (380 lb).4. Put clean engine oil on the threads of all the cylinder head bolts. Install bolts (14). Do not tighten at this time.
(1) Large bolts (3/4 inch). Put 6V-4876 Molycoat Paste Lubricant on bolt threads and between washer and underside of bolt bolt heads. (2) Small bolts (3/8 inch). See Step 5h.5. Use the tightening sequence below to tighten the bolts that hold the 3408 Engine cylinder head in position.a. Tighten bolts 1 through 10 in number sequence to 270 25 N m (200 20 lb ft).b. Tighten bolts 1 through 10 in number sequence to 470 20 N m (345 15 lb ft).c. Tighten bolts 1 through 10 in number sequence to 470 20 N m (345 15 lb ft).d. Install the rocker arm shafts for the engine valves and the remaining (3/4 in) bolts and/or compression brake studs.e. Tighten bolts 11 through 18 in number sequence to 270 25 N m (200 20 lb ft).f. Tighten bolts 11 through 18 in number sequence to 450 20 N m (330 15 lb ft).g. Tighten bolts 11 through 18 in number sequence to 450 20 N m (330 15 lb ft).h. Tighten the nine small bolts (2) to a torque of 45 7 N m (33 5 lb ft). 6. Install support (12).7. Connect hose clamp (13) to exhaust manifold. 8. Install bolt (10) and support (11). Install the remaining ten bolts and the supports along the intake side of the cylinder head. Torque all twelve bolts (10) to 43 7 N m (32 5 lb ft).9. Install bolt (9) to timing advance housing. 10. Put the gasket in position. Install three bolts (2) and water lines group (1).11. If removed, install the O-ring seal to sensor (3). Install bolt (4) and sensor (3).12. Connect connector (6).13. Install bolt and locknut (5).14. If removed, install the O-ring seal to sensor (7). Install sensor (7) to cylinder head (8). Step 15 is for the 3408 Industrial Engine only.15. Install the valve cover base. Use the tightening sequence above and tighten the bolts to a torque of 14 4 N m (10 3 lb ft). Step 16 is for the 3412 Industrial Engine only.16. Install the two valve cover bases. Use the tightening sequence above and tighten the bolts to a torque of 14 4 N m (10 3 lb ft).17. Fill the cooling system with coolant to the correct level. See the Operation & Maintenance Manual.End By:a. install turbochargersb. install rocker shaft assemblies