9.1 - | Crankcase assembly: external components

1 | Key

2 | Timing gear pair

3 | Lock washer

4 | Hex nut

5 | Key

6 | Aluminium gasket

7 | Special screw

8 | Aluminium gasket

9 | Plug

10 | Breather valve

11 | O-ring

12 | Cylinder barrel-head stud bolt

13 | Locating dowel

14 | Plug

15 | Plug

16 | Sealing washer, thickness 2

17 | Nipple

18 | Gauze pickup filter

19 | Neutral switch

20 | Seal

21 | Gear shaft

22 | Washer

23 | Starter motor gear

24 | Washer

25 | Circlip

26 | Screw

27 | Plug

28 | Seal

29 | Seal

30 | Screw

31 | Screw

32 | Washer

33 | O-ring

34 | Pickup sensor

35 | Seal

36 | Plug

37 | Seal

38 | Ball

39 | Spring

40 | Bush

Parts catalogue

Timing system
Filters and oil pump
Crankcase halves
Electric starting and ignition
Gearchange CONTROL

Important
Bold reference numbers in this section identify parts not shown in the figures alongside the text, but which can be found in the exploded view diagram.
Removal of external components

Operation | Section reference
Remove the engine from the frame | N 1, Removal of the engine
Remove the lubrication system | N 2.1, Removal of the oil pump
Remove the cylinder head assemblies and the timing parts | N 4.2, Cylinder head assemblies: timing belt covers/timing system
Remove the cylinder barrel/piston assemblies | N 5, Removal of the cylinder/piston assembly
Remove the starter motor | P 3, Removal of the starter motor

Notes
The following removal operations are required in order to renew and/or clean the crankcase halves. If the original crankcase halves are to be reused, then the removal of these components is not essential.
Unscrew the screw (30) and remove the oil breather valve (10) with the O-rings (11). Check the condition of O-rings (11) and renew them if necessary.
Unscrew and remove the two plugs (14) from the clutch–side crankcase with the relative seals (8).
Unscrew and remove the oil filter cartridge (Sect. D 4, Changing the engine oil and filter cartridge).
Unscrew and remove the oil filter support nipple (17).
Undo and remove the earth cable screw (7) with its seal (6).
Remove the gauze pickup filter (18) with its seal from the clutch-side crankcase half as described in Sect. D 4, Changing the engine oil and filter cartridge.
Unscrew the plug (27), taking care to recover the relative seal (28).
Remove drain plug (9) with its seal (29).
Remove the neutral switch (19) with seal (20).
Remove the cylinder head studs (12) with the aid of the appropriate tool.
Remove the gear interlock pawl and plunger as described in Sect. N 7.1, Disassembly of the gear interlock plunger and pawl assembly.
To remove the engine sensor (34), unscrew the screw (31) and recover the washer (32).
Check the condition of the O-ring (33) in the crankcase half and the O-ring (A) on the sensor (34) and renew them if necessary.
Remove the bush (40) and recover the seal (37), the spring (39) and the ball (38).
Refitting the external components
Check the condition of O-rings (11) and renew if necessary.
Install the oil vapour breather valve (10) in the crankcase along with O-rings (11), previously lubricated.
Tighten the screw (30) to the specified torque (Sect. C 3, Engine torque settings).
Tighten the two plugs (14) with the seals (8) to the specified torque (Sect. C 3, Engine torque settings).
Apply the recommended threadlocker to the nipple (17).
Tighten the oil filter support nipple (17) to the specified torque (Sect. C 3, Engine torque settings).
Screw in the drain plug (9) with its seal (29) and tighten to the specified torque (Sect. C 3, Engine torque settings), after applying the recommended threadlocker.
Refit the neutral switch (19) with its seal (20) and tighten to the specified torque (Sect. C 3, Engine torque settings).
Apply threadlocker to the plug (27), fit it with its seal (28) and tighten to the specified torque (Sect. C 3, Engine torque settings).
Refit the gauze pickup filter (18) with its seal as described in Sect. D 4, Changing the engine oil and filter cartridge.
Refit the gear interlock pawl and plunger (Sect. N 7.1, Refitting the gear interlock plunger and pawl assembly).
Now fit the studs (12) in the crankcase halves, applying threadlocker and tightening to the specified torque value (Sect. C 3, Engine torque settings). Use a tool of the type shown in the illustration.
Check that the O-ring (33) is installed in the crankcase.
Grease the engine pickup (34) in the area indicated and check that the O-ring (A) is installed.
Fit the engine pickup (34) in its seat in the crankcase.
Insert the screw (31) with the washer (32) and tighten to the specified torque (Sect. C 3, Engine torque settings).
Use a feeler gauge to check the clearance between the engine pickup (34) and the timing gear (2). The value must be between 0.6 and 0.8 mm.
Fit the earth lead retaining screw (7) with the seal (6) in the crankcase and tighten to the specified torque (Sect. C 3, Engine torque settings).
Insert the ball (38) and the spring (39) in the crankcase and screw in th bush (40) with its seal (37), tighteing it to the specified torque (Sect. C 3, Engine torque settings).
If removed, fit the seal (16) to the service plug (15): the seal must be oriented so that the square edge faces the clutch-side crankcase.
Apply the recommended threadlocker to the thread of the plug (15) and tighten it to the specified torque (Sect. C 3, Engine torque settings).

Operation | Section reference
Refit the starter motor | P 3, Refitting the starter motor
Refit the cylinder barrel/piston assemblies | N 5, Refitting the cylinder/piston assembly
Refit the cylinder head assemblies and the timing parts | N 4.2, Cylinder head assemblies: timing belt covers/timing system
Refit the lubrication system | N 2.1, Refitting the oil pump
Refit the engine to the frame | N 1, Refitting the engine

Removal of the timing gears

Operation | Section reference
Remove the alternator-side crankcase cover and the alternator assembly | N 8, Flywheel - alternator

Slide out driving gear (A) of timing gear pair (2) and remove the Woodruff key (5).
Relieve the staking on the lock washer (3) of the nut (4).
Restrain the driven timing gear by inserting a pin in one of the holes, and unscrew the nut (4).
Remove the nut (4), washer (3), driven timing gear (B) and Woodruff key (1) from the timing belt driveshaft shaft.
Refitting the timing gears
Before refitting, check the wear on the timing gear pair (2) and renew if necessary.
Important
The timing gears (2) must always be renewed as a pair.
Refitting is the reverse of removal.
Important
On completion of the refitting operations, check that tab washer (3) is staked against nut (4) in such a way as to prevent the nut from working loose.

Operation | Section reference
Refit the alternator-side crankcase cover and alternator assembly | N 8, Flywheel - alternator

Removal of the starter motor idler gear

Operation | Section reference
Remove the flywheel/alternator assembly | N 8, Flywheel - alternator

Remove the circlip (25) and the washer (24).
Remove the starter motor idler gear (23) and shim (22).
Undo the screw (26) securing the idler gear shaft (21) and remove the shaft.
Refitting the starter motor idler gear
Refitting is the reverse of removal.
Notes
Apply the prescribed threadlocker to the screw (26) and tighten to the prescribed torque (Sect. C 3, Engine torque settings).

Operation | Section reference
Refit the flywheel/alternator assembly | N 8, Flywheel - alternator