Reassembling the cylinder head
The exhaust side can be recognised by the presence of three threaded holes (A) on the flange and a recess to fix the secondary air cover (B).
The intake side can be identified by the presence of threaded holes (C) on the flange.
All the figures in this chapter refer to a vertical cylinder head.
Valve guide sealing rings
Position the cylinder head on the appropriate support 88713.2103.
Use denatured alcohol to lubricate the valve guide sealing rings (14) and insert them from the spring side onto tool (L) no. 88713.2442.
Fit the end of the tool into the valve guide and use a hammer to tap the sealing rings (14) home into the valve guides.
Reassembling the closing rocker arms
Check that the rocker arms are not scored or show signs of breakage in the area of contact with the camshaft and shim.
The closing rocker arm shafts (17) feature a 10 mm diameter, whereas the opening rocker arm shafts (13) feature a 9 mm diameter.
Using an M6 screw, position the closing rocker shaft (17) towards the exhaust side of the cylinder head.
Locate the spacer (18) on the shaft.
Place spring (16) on spacer (18), as shown in the figure, by engaging one end in the relevant seat on the cylinder head.
Place the closing rocker arm (5) in its seat having care that the through hole is aligned with the closing rocker arm shaft; then push the shaft fully home.
Proceed in a similar manner to install the closing rocker arm (6) with the spring (15).
Load the springs (16) and (15) on the closing rocker arms (5) and (6) respectively using the tool no. 88713.2069.
Fit closing rocker arms (6) and (5), the relevant springs and the relevant shafts on the exhaust side as for the intake side.
Note
Always install the closing rocker arms on the exhaust side before those on the intake side.
Warning
Take care not to damage the shoe of the closing rocker arm with the intake spring during assembly.
Refitting valves, closing shims and split rings
Carefully clean the two intake valve seats (D) and the two exhaust valve seats (E). Use engine oil to lubricate the central part of the two intake valve (9) and of the two exhaust valve (10) stems.
Warning
Apply engine oil on the valve stems only in the indicated area, having care not to oil the groove.
Fit the valves in their seats on cylinder head, fully home.
Hold the closing rocker arm (5) pushed downwards and fit the closing shim (7) on the valve stem up to reach the rocker arm. If using the old cylinder head, start by refitting the original shim.
Insert the new split rings (8) in the valve groove (T) and release the rocker arm to correctly position shim (7).
Turn the closing rocker arm (5), and compress the spring as much as possible while holding valve, shim and split rings in the valve closed position.
Release the rocker arm with a quick movement, so that the split rings seat in the shim.
Repeat the procedure with the opposite valve and check that the top of the valve stem is aligned with the surface of the shim (7); if it is not the case, repeat the split ring installation procedure.
Install the closing shims on the intake valves (9) using the method described above for the exhaust valves.
Refit the camshafts (Refitting the camshafts) to check the valve clearance when closed.
Refitting the opening shims and opening rocker arms
Using an M6 screw, position the opening rocker arm shaft (13) (diameter 9 mm).
Locate the opening rocker arm (3) and drive the shaft home.
Install the four rocker arms (3) as described above.
Raise the opening rocker arm (3) and install the opening shim (4) fully against the valve stem.
Release the rocker arm so that it rests against the shim.
Ensure the shim is correctly seated by lightly tapping the rocker arm shoe (G) with plastic mallet.
Refit the camshafts and check the valve clearance when open.
Insert the gaskets (12) on the opening and closing rocker arm shaft plugs (11), orienting them (preferably) with the square edge side (T) facing the cylinder head.
Apply the recommended threadlocker on the plug (11) threads: apply the product on the first two plug threads, spreading it for the half circumference (about 180°).
Tighten the plugs to a torque of 15 Nm (Min. 14 Nm - Max. 16 Nm).
Note
After tightening, remove any excess of product.
Refit the camshaft supports (Refitting the camshafts).
Refit the timing pulleys (Refitting the timing layshaft pulley).
Refit the cylinder head covers (Refitting the camshafts).
Refit the coils.
Refit the complete head (Fitting the complete heads).