33981T 1 Mercruiser SLIDE

START BY:a) remove valve covers 1. Use tool (A) to loosen the nuts and remove fuel lines (2).2. Disconnect fuel lines (1) from the valve cover base adapters.
Put protection caps (5F2807) and plugs (2F2990) on the fuel line openings to keep dirt and foreign material out of the fuel system.
3. Remove locks (3) and fuel line adapters (4) from the valve cover bases for clearance to remove the rocker shaft bolts. 4. Remove bolts (5) and rocker shaft assemblies (6) from the cylinder head. 5. Remove push rods (7) from the cylinder heads.6. Put identification on each valve bridge as to its location. Remove valve bridges (8) from the cylinder heads.Install Rocker Shaft Assemblies
1. Put clean engine oil on the bridge dowels, push rods (2) and inside bridges (1). Install bridges (1) and push rods (2) in the correct positions. 2. Push straight down on the top contact surface of valve bridge (1) with a force of 4 to 45 N (1 to 10 lb). Turn the adjustment screw clockwise until contact is made with the valve stem. Turn the adjustment screw 20° to 30° more to keep bridge (1) straight on the dowel. Hold the adjustment screw in this position and tighten the locknut to a torque of 28 4 N m (22 3 lb ft). 3. Put rocker shaft assembly (3) in position on the cylinder head. Make sure the adjustment screws in the rocker arms are correctly engaged with the push rods. 4. Put clean engine oil on the threads of the bolts and install the bolts to hold rocker shaft assembly. Tighten the bolts as follows:a) Tighten bolts 1 through 6 in number sequence shown to a torque of 270 25 N m (200 20 lb ft).b) Tighten bolts 1 through 6 in number sequence shown to a torque of 447 20 N m (330 15 lb ft).c) Tighten bolts 1 through 6 in number sequence shown again to a torque of 447 20 N m (330 15 lb ft). 5. Put clean engine oil on the O-ring seals and install fuel line adapters (5), the washers, spacers, locks and nuts (4). Tighten nuts (4) to a torque of 14 3 N m (10 2 lb ft). 6. Install fuel lines (7) and connect fuel lines (6) to the fuel line adapters. Use tool (A) and tighten the nuts for fuel lines (7). Tighten all fuel line nuts to a torque of 40 7 N m (30 5 lb ft).7. 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 valve covers Rocker Shaft Assemblies Disassemble Rocker Shaft Assemblies
START BY:a) remove rocker shaft assemblies 1. Remove retainer (1) from the end of the shaft.2. Remove the washers and rocker arm (2). 3. Use tool (A) to remove the pin that holds bracket (3) to the rocker arm shaft.4. Remove bracket (3), rocker arm (4) and the spring.5. Remove the remainder of the rocker arms. The center brackets do not have pins.Assemble Rocker Shaft Assemblies
Make sure all parts of the rocker shaft assembly are clean before assembly. 1. Put clean engine oil on shaft (3).2. Install the center springs, rocker arms and bracket.3. Install spring (1), rocker arm (4) and bracket (2).4 Put tape around the shaft on each side of bracket (2) as shown. Put the hole in bracket (2) in alignment with the hole in shaft (3). Put a mark on each piece of tape in alignment with the hole in bracket (2).5. Install pin (5) until it is extended 8.6 mm (.34 in) above the surface of bracket (2). Make sure pin (5) is in alignment with the marks on the tape before pin is installed. Remove the tape. 6. Install rocker arm (6), washers (7) and retainer (8). Install enough washers until the end play on each end of the shaft is 0.12-1.01 mm (.005-.040 in).END BY:a) install rocker shaft assemblies