Overhauling the crankcase halves
Remove the engine from the frame (Removing the engine).
Remove the timing outer covers (Removing the timing outer covers).
Remove the timing belts (Removing the tensioner pulley/timing belt).
Remove the timing belt pulleys (Disassembling the camshaft pulleys).
Remove the complete cylinder head unit (Removing the engine heads).
Remove the cylinder/piston assembly (Removing the cylinder/piston assembly).
Remove the generator side cover (Removing the generator cover) and the complete generator (Removing the flywheel/generator unit).
Remove the starter motor (Removing the starter motor).
Remove the clutch cover (Removing the clutch cover).
Remove the clutch unit (Removing the clutch).
Remove the oil pump (Removing the oil pump).
Remove the primary drive gear (Removing the primary drive gear).
Remove the mesh filter (Changing engine oil and filter cartridge).
Separate the crankcase halves (Separating the crankcase halves).
Visually inspect the engine crankcase halves (12) and (13).
Important
If crankcase halves have to be replaced, they are supplied in pairs as spare parts.
Check that the surfaces of the crankcase halves are perfectly flat using a reference surface. Check that the bearings (14) and (15) are in good condition. Main bearings must always be replaced in pairs).
Warning
When overhauling an engine it is good practice to renew all the crankcase half bearings.
Replace gearbox secondary shaft end bearings (16) and (17) and timing layshaft bearings (18) and (19).
Replace gearbox primary shaft bearings (20) and (21).
At each overhaul it is recommended to replace also the sealing ring (22) between bearing (20) and chain-side crankcase half (12).
During assembly, lubricate seal (22) with KLÜBERPLUS S 06/100 (or denatured alcohol), drive it fully home against the crankcase half, and aim it as shown.
Make sure that seal positioning height is:
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oil seal (B) height 4 ± 0.2 mm;
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oil seal (C) positioning 67 ± 0.2 mm;
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(D) 5.0 ÷ 5.02 mm;
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(E) 66.0 ÷ 66.05 mm.
At each overhaul it is recommended to replace also the sealing ring (23) on the outside of bearing (16).
During assembly, lubricate sealing ring (23) with KLÜBERPLUS S 06/100 (or denatured alcohol), and fit it as shown.
At each overhaul it is recommended to replace also the sealing ring (24) on the outside of bearing (19).
If swingarm shaft needle roller bearings have been removed, insert snap ring (25) in its seat (G) on crankcase half (12) or (13) hole (F).
Smear hole (F) with recommended grease.
Install sealing ring (26) and needle roller bearings (27) e (28), complying with the value (H) of 4.8 ÷ 5.0 mm, and making sure that the three parts are fully home with one another.
While driving the three parts, aim them as follows:
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sealing ring (26) must be aimed as shown;
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needle roller bearing (27) must be aimed with the "wordings" side (L) facing the crankcase half;
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needle roller bearing (28) must be aimed with the "wordings" side (L) facing up;.
Drive sealing ring (29), aiming it as shown in figure "D", fully home inside needle roller bearing (5).
Smear needle roller bearing inner surfaces with recommended grease.
Check the condition of locating bushes (30). If apparently distorted or loose in their seats, change them using proper tools.
When the locating bushes (30) are hard to remove from casing, use a left-hand tap to force bushes out.
Important
The bushes must always be replaced when they have been removed using the above procedure.