Valve springs

Valve springs

Thoroughly clean the valve springs of oil deposit and inspect for cracks. It is advisable to check the free spring height and if this dimension differs from the original height, details of which are given in Technical Data, the spring must be renewed. Any decrease in length indicates that the spring has weakened.

Reassembly of the cylinder head

Reassembly is the reverse procedure to dismantling. During assembly utmost cleanliness must be observed as any abrasive material could find its way to the pistons and cylinder bores causing unnecessary wear. Check that the cylinder barrel mating face is clean to ensure correct gasket sealing.

Cylinder head installation

To refit the cylinder head proceed as follows:

1. Place a new cylinder head joint on the cleaned faces of

the cylinder barrels. Insert the rocker pushrod and lubrication pipe sleeves together with the relevant gaskets and rings.

2. Fit the washers and nuts to the studs and tighten to fingertight.
3. Tighten the nuts in the order shown in FIG 1:44 and FIG 1:46 to a torque wrench setting of 18.1 lb ft. Reset the torque wrench to a new setting of 23.9 lb ft and tighten the nuts once more in the recommended order. Replace the pushrods in the correct order.
4. Refit the rocker shaft ensuring correct location of the lubrication tube to the rocker shaft and replace the plain and lockwashers. Tighten the nuts to a torque wrench setting of 15.2 lb ft. Reset the tappet to rocker clearance adjustment.
5. Connect the two exhaust side manifolds to the cylinder head. Using new gasket refit the spark plugs and HT cables. Replace the rocker cover fitted with a new cork gasket and blower conveyor to the cylinder head securing screws. Refit the carburetter and reconnect its fuel line and controls. Refit the air cleaner and elbow and connect the rocker cover breather pipe (if fitted).