105671-0490 ZEXEL 9 420 615 212 BOSCH AUTOM. ADVANCE MECHANISM 9420615212 1056710490 1681017d01

Start By:a. remove valve covers 1. Remove bolts (1) that hold the valve cover bases to the cylinder head assembly. Remove valve cover bases (2). 2. Use tool (A) to loosen fuel injection line (3) from fuel injection nozzle (4). 3. Use tool (B) to loosen the nut at the fuel injection line adapter end. Remove inner fuel injection lines (3). Install caps and plugs on all fuel injection line openings to keep dirt out of the fuel system. 4. Remove bolts (5) that hold the rocker shaft assemblies to the cylinder head assembly.5. Remove rocker shaft assemblies (6). 6. Put identification marks on the push rods as to their location in the engine. Remove push rods (7). 7. Put identification marks on the bridges as to their location in the engine. Remove bridges (8) from the dowels on the cylinder head assembly.Install Rocker Shaft Assemblies And Push Rods
1. Put clean engine oil on the bridges and dowels. Install the original bridges in their respective locations. New bridges can be mixed.2. Install bridges (8) on the bridge dowels. While firmly pressing 0.5 to 4.5 kg (1 to 10 lb.) straight down on the top contact surface of the bridge, turn the adjusting screw clockwise until contact is made with the valve stem. Turn the screw an additional 20° to 30° (1/3 to 1/2 of 1 hex on nut). This will straighten the dowel in the guide and compensate for the slack in the threads. Hold the adjusting screw in this position, and tighten the locknut to a torque of 30 4 N m (22 3 lb.ft.). Install original push rods in their respective locations in the engine. New push rods can be mixed.3. Install push rods (7). 4. Put rocker shaft assemblies (6) in position on the cylinder head assembly.5. Put clean engine oil on the threads of bolts (5) that hold the shaft assemblies in place. Tighten the bolts first to a torque of 270 25 N m (200 18 lb.ft.). Start with the bolt in the center of the rocker shaft assembly. Tighten the bolts again to a torque of 450 20 N m (330 15 lb.ft.). Tighten the bolts again by hand to a torque of 450 20 N m (330 15 lb.ft.).
Do no cause damage to the O-ring seals on the inner fuel lines.
6. Install inner fuel injection lines (3). Tighten the fuel injection line adapter nuts (9) to a torque of 40 7 N m (30 5 lb.ft.) with tool (B).7. Tighten fuel injection line nut (10) to a torque of 40 7 N m (30 5 lb.ft.) with tool (A).8. Make adjustments to the valves until the intake valve clearance is 0.38 mm (.015 in.) and the exhaust valve clearance is 0.76 mm (.030 in.). See Valve Clearance Setting in Testing And Adjusting. Tighten the locknut to a torque of 30 4 N m (22 3 lb.ft.) and