19740 Mercruiser NUT

Start By:a. remove valve cover basesb. remove rocker shaft assembliesc. remove water temperature regulator housingsd. remove exhaust manifolds
(D9L)
(D10N)1. Disconnect air-fuel ratio control air line (1), wiring harness (2) and the clips from the right cylinder head (D9L).2. Remove the bolts from clip (13) and brackets (12). Remove bolts (11) and tube assembly (10). (D10N).3. Remove lifting bracket (3) from each cylinder head. 4. Remove brackets (4) and supports (5) from each side of the engine.
Make sure the pins are installed in the levers of the fire suppression agent cylinders so the fire suppression system will not activate. Personal injury can be the result if the fire suppression system is activated when hose (6) is disconnected.
5. Disconnect hose (6) from the fire suppression nozzle.6. Remove bracket (7) from the engine. 7. Remove four of the cylinder head bolts and install tooling (A) on the cylinder head with four 3/8" - 16 NC bolts 2 in. long as shown. 8. Fasten a hoist to cylinder head (8). Remove the remainder of the bolts and remove cylinder head (8). The weight of cylinder head (8) is 135 kg (300 lb.).
Do not put the cylinder head assembly down on a flat surface. This can cause damage to the fuel injection valves.
The following steps are for the installation of the cylinder heads. Make sure a new gasket has been installed between the spacer plate and cylinder block. See Remove And Install Spacer Plates.9. Thoroughly clean the spacer plate and the bottom surface of the cylinder head. Install a new cylinder head gasket.10. Fasten tooling (A) to the cylinder head with four 3/8" - 16 NC bolts 2 in. long as shown. Fasten a hoist to the cylinder head. Put cylinder head (8) in position on the engine. 11. Put clean engine oil on all bolt threads and tighten the bolts in the following sequence.a. Tighten bolts 1 through 20 in number sequence to a torque of 280 27 N m (210 20 lb.ft.).b. Tighten bolts 1 through 20 in number sequence to a torque of 440 20 N m (320 15 lb.ft.).c. Tighten bolts 1 through 20 in number sequence again to a torque of 440 20 N m (320 15 lb.ft.). 12. Install rocker shaft assemblies (9) on the cylinder head. Put clean engine oil on all bolt threads and tighten the bolts in the following sequence: a. Tighten bolts 21 through 26 in number sequence to a torque of 280 27 N m (210 20 lb.ft.).b. Tighten bolts 21 through 26 in number sequence to a torque of 440 20 N m (320 15 lb.ft.).c. Tighten bolts 21 through 26 in number sequence again to a torque of 440 20 N m (320 15 lb.ft.).13. Install the 3/8" - 16 NC bolts in the cylinder head and tighten to a torque of 44 7 N m (32 5 lb.ft.).14. Install bracket (7) and connect hose (6) to the fire suppression nozzle. Before the machine is operated, make sure the pins are removed from the fire suppression agent cylinder levers so the system can be activated if needed.15. Install brackets (4) and support (5) on each side of the engine.16. Install lifting brackets (3) on each cylinder head. Install O-ring seals on each end of tube assembly (10) and bolts (11). Install brackets (12) and clip (13) (D10N).17. Connect air line (1), wiring harness (2) and the clips to the right cylinder head.18. Install the valve bridges and make sure they are in correct adjustment. See Install Rocker Shaft Assemblies for the valve bridge adjustment.19. Install the push rods and use tool (B) to make a connection of the rocker arms with the push rods.20. Make an adjustment of the valves to have a clearance of 0.38 mm (.015 in.) for intake and 0.76 mm (.030 in.) for exhaust. See Valve Clearance Setting in Testing And Adjusting.End By:a. install exhaust manifoldsb. install water temperature regulator housingsc. install valve cover bases