SOHC models
Removal
1 Disconnect the battery negative lead.

2 Partially drain the cooling system.

3 Remove the air cleaner.

4 Disconnect the coolant hoses from the automatic choke (where applicable), and the inlet manifold. Identify the hose locations for use when refitting.

5 Disconnect the fuel supply hose at the carburettor and plug the end to minimise petrol spillage.

6 Disconnect all relevant wiring and vacuum pipes from the carburettor, if necessary noting the locations for use when refitting.

7 Disconnect the throttle cable from the throttle linkage.

8 Disconnect the crankcase ventilation and brake servo vacuum hoses from the inlet manifold. The brake servo vacuum hose is secured with a union nut (see illustrations).

25.8a Disconnecting the crankcase ventilation . . .

25.8b . . . and brake servo vacuum hoses from the inlet manifold - SOHC models

9 Disconnect any remaining wiring and vacuum pipes from the inlet manifold, if necessary noting the locations as an aid to refitting.

10 Where necessary, unbolt the throttle cable bracket from the top of the inlet manifold for improved access, and unbolt the dipstick tube bracket.

11 Unscrew the two nuts and four bolts securing the manifold to the cylinder head, noting the location of the rear engine lifting bracket (see illustration).

25.11 Rear engine lifting bracket location - SOHC models

12 Lift the inlet manifold from the cylinder head, and recover the gasket (see illustration).

25.12 Lifting the inlet manifold from the cylinder head - SOHC models

13 If desired, the carburettor can be removed from the inlet manifold by unscrewing the securing nuts or screws. Refer to the relevant Section describing carburettor removal and refitting. Recover the gasket.

Refitting
14 Refitting is a reversal of removal bearing in mind the following points.

15 Ensure that all mating faces are clean.

16 Renew the gasket(s), and apply a bead of sealant at least 5.0 mm (0.2 in) wide around the central coolant aperture on both sides of the manifold-to-cylinder head gasket.

17 Tighten the manifold securing nuts and bolts progressively to the specified torque, ensuring that the engine lifting bracket is in place.

18 Make sure that all hoses, pipes and wires are correctly reconnected, and if the fuel supply hose was originally secured with a crimped type clip, discard this and use a new worm drive clip on refitting.

19 On completion, refill the cooling system, adjust the throttle cable and check and if necessary adjust the idle speed and mixture.

DOHC models
Removal
20 Disconnect the battery negative lead.

21 Partially drain the cooling system.

22 Remove the air cleaner.

23 Disconnect the coolant hoses from the thermostat housing and the inlet manifold, noting their locations to assist with refitting.

24 Disconnect the fuel supply and return hoses from the carburettor. Plug their ends to minimise petrol spillage.

25 Release the coolant hose from the bracket under the automatic choke housing.

26 Disconnect the HT leads from the spark plugs, and move them to one side.

27 Disconnect all relevant wiring and vacuum pipes from the carburettor, thermostat housing and inlet manifold, noting the locations as an aid to refitting.

28 Disconnect the crankcase breather hose from the inlet manifold.

29 Disconnect the throttle cable from the throttle linkage.

30 Make a final check to ensure that all relevant wires, pipes and hoses have been disconnected to facilitate removal of the manifold.

31 Unscrew the ten bolts and two nuts securing the manifold to the cylinder head.

32 Lift the manifold clear of the cylinder head. Recover the gasket.

33 Recover the two plastic spark plug spacers from the recesses in the cylinder head.

34 If desired, the carburettor can be removed from the manifold by unscrewing the securing screws. Refer to the carburettor removal and refitting Sections as necessary.

Refitting
35 Refitting is a reversal of removal, bearing in mind the following points.

36 Ensure that all mating faces are clean.

37 Ensure that the spark plug spacers are in position in the cylinder head recesses before refitting the manifold.

38 Renew all gaskets.

39 Tighten all manifold securing nuts and bolts progressively to the specified torque.

40 Make sure that all hoses, pipes and wires are securely reconnected in their original positions.

41 On completion, refill the cooling system.

Check the adjustment of the throttle cable.

Check, and if necessary adjust, the idle speed and mixture.

CVH models
Removal
42 Proceed as described in paragraphs 1 to 3 inclusive.

43 Disconnect the coolant hoses from the automatic choke, thermostat housing and inlet manifold, noting their locations for use when refitting.

44 Disconnect the fuel supply hose at the carburettor and plug the end to minimise petrol spillage.

45 Disconnect all relevant wiring and vacuum pipes from the carburettor, thermostat housing and inlet manifold, noting the locations as an aid to refitting.

46 Disconnect the throttle cable from the throttle linkage.

47 Unbolt the dipstick tube from the inlet manifold and withdraw the dipstick and dipstick tube from the cylinder block.

48 Unscrew the seven nuts securing the manifold to the cylinder head, then lift the manifold from the cylinder head, and recover the gasket.

49 If desired, the carburettor can be removed from the manifold by removing the securing screws. Recover the insulator block (see illustrations).

25.49a Removing the carburettor . . .

25.49b . . . and the insulator block from the inlet manifold - CVH models

50 The carburettor intermediate plate can be removed from the manifold by unscrewing the three securing screws. Recover the gasket.

51 If necessary, the thermostat and housing can be removed from the manifold.

Refitting
52 Refitting is a reversal of removal, bearing in mind the following points.

53 Ensure that all mating faces are clean and renew the gasket(s).

54 Tighten the manifold securing nuts progressively to the specified torque.

55 Make sure that all hoses, pipes and wires are correctly reconnected, and if the fuel supply hose was originally secured with a crimped type clip, discard this and use a new worm drive clip on refitting.

56 On completion, refill the cooling system, adjust the throttle cable and check and if necessary adjust the idle speed and mixture.