24.5 Enlarging ring end gap with the file clamped in a vice

checked/corrected, the rings can be installed on the pistons.

9 The oil control ring (lowest on the piston) is installed first. It is composed of three separate components, namely the expander and the upper and lower side rails. Slip the expander into the groove, then install the lower side rail. Do not use a piston ring installation tool on the oil ring side rails as they may be damaged. Instead, place one end of the side rail into the groove between the expander and the ring land. Hold it firmly in place and slide a finger or thin blade around the piston while pushing the rail into the groove. Next, install the upper side rail in the same manner (see illustrations). Make sure the ends of the expander do not overlap.

24.9a

lower and upper rails with the aid of a thin blade

2*42 Engine, clutch and transmission

MARK

24.11 Check that the compression rings are the right way up before fitting

10. After the three oil ring components have been installed, check to make sure that both the upper and lower side rails can be turned smoothly in the ring groove.

11. The upper surface of each compression ring should be marked at one end near the gap (see illustration 23.6b). Make sure that the identification mark or letter is facing up. Fit the middle ring (2^nd compression ring) into the middle groove in the piston. Do not expand the ring any more than is necessary to slide it into place. To avoid breaking the ring, use a piston ring installation tool or the method described in Step 9 (see illustration).

12. Finally, install the top ring in the same manner into the top groove in the piston. Make sure the identification letter near the end gap is facing up.

13. Once the rings are correctly installed, check they move freely without snagging and stagger their end gaps as shown (see illustration).

25 Crankshaft and main bearings - removal, inspection and installation

Note: To remove the crankshaft the engine must be removed from the frame.

Removal

1. Remove the engine from the frame (see Section 5). Remove the cylinder head (see Section 10) and separate the crankcase halves (see Section 20).

2. Separate the connecting rods from the crankshaft (see Section 22). Note: If no work is to be carried out on the piston/connecting rod assemblies there is no need to remove them from the cylinders. Remove the connecting rod bearing caps (see Section 22, Steps 3 and 4) and push the pistons up the bores so that the connecting rod ends are clear of the crankshaft. Wrap clean rag around the connecting rods to prevent damage to the cylinder bores.

3. Ensure the camchain is free to be lifted out of the engine and lift the crankshaft with the camchain attached out of the upper crankcase half, taking care not to dislodge the

TOP RING Q

OIL RING m

SPACER

SECOND (MIDDLE) RING 0