Make sure the gasket locates onto the dowels (A) and the UP mark (B) reads correctly

Tighten the cylinder head nuts as described to the specified

Torque

it locates correctly onto the dcwels, and, where appropriate, the •UP' mark stamped out of the gasket is positioned along the rear edge and is the correct way up (see illustration). Never re-use the old gasket.

12 Carefully fit the cylinder head onto the block, making sure it locates correctly onto the dowels (see illustration 10.6).

13 Install the twelve nuts and the two bolts and tighten them all finger-tight (see illustration 10.5a). When installing the nuts, locate them slightly in from the stud, then slide them onto the stud so the base rim fits under the casting (see illustration 10.5b). First tighten the nuts evenly and a little at a time in a criss-cross pattern, starting from the centre and working outwards, to the torque setting specified the beginning of the Chapter (see illustration). Now tighten the bolts to the specified torque.

14 Fit a new O-ring onto each coolant pipe, then press the pipes into their bores and secure them with the bolts (see illustration).

15 Lubricate each shim with molybdenum disulphide oil (a 50/50 mixture of molybdenum disulphide grease and engine oil) and fit it into Its recess In the top of the valve, with the size marking on each shim facing up (see illustration). Check that the shim is correctly seated, then lubricate the folower with

molybdenum disulphide oil and install it onto the valve (see illustration). Note: It is most important that the shims and followers are returned to their original valves otherwise the valve clearances will be inaccurate.

16 Install the camshafts (see Section 9).

17 Install the engine (see Section 5).

^ | ^

11 Valves/valve seats/valve guides - servicing

1 Because of the complex nature of this job and the special tools and equipment required, most owners leave servicing of the valves. valve seats and valve guides to a professional.

2 The home mechanic can, however, remove the valves from the cylinder head, clean and check the components for wear and assess the extent of the work needed, and, unless a valve service is required, grind in the valves (see Section 12).

3 The dealer or motorcycle engineer will remove the valves and springs, renew the valves and guides, recut the valve seats, check and renew the valve springs, spring retainers and collets (as necessary), renew the valve seals and reassemble the valve components.

4 After the valve service has been performed, the head will be in like-new condition. When the head is returned, be sure to clean it again very thoroughly before installation on the engine to remove any metal particles or abrasive grit that may still be present from the valve service operations. Use compressed air, If available, to blow out all the holes and passages.

12 Cylinder head and valves -

disassembly, inspection and reassembly

1 As mentioned in the previous section, valve servicing, valve seat re-cutting and valve guide renewal shoulc be left to a dealer or motorcycle engineer. However, disassembly, cleaning and inspection of the valves and related components can be done (if the necessary special tools are available) by the home mechanic. This way no expense is incurred if the inspection reveals that overhaul is not required at this time.

2 To disassemble the valve components without the risk of damaging them, a valve spring compressor is absolutely necessary.

).14 Fit the pipes using new O-rings

Дата добавления: 2015-10-29