4.2 - | Cylinder head assemblies: timing belt covers/timing system

1 | Vertical cylinder timing belt cover

2 | Horizontal cylinder timing belt cover

3 | Screw

4 | Screw

5 | Spacer

6 | Elastic-stop ring

7 | Washer

8 | Outer timing belt driveshaft pulley

9 | Horizontal cylinder timing belt

10 | Intermediate spacer

11 | Idler pulley assembly

12 | Screw

13 | Elastic-stop nut

14 | Washer

15 | Special washer

16 | Camshaft pulley

17 | Flange

18 | Screw

19 | Screw

20 | Screw

21 | Tensioner pulley assembly

22 | Inner timing belt driveshaft pulley

23 | Vertical cylinder timing belt

24 | Key

25 | Circlip

26 | Key

27 | Screw

Parts catalogue

timing system
Cylinder head: timing system

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 the timing belt covers

Operation | Section reference
Remove the fuel tank | L 2, Removal of the fuel tank
Remove the hoizontal cylinder exhaust pipe | L 8, Removal of the exhaust system

Unscrew the screw (4) and screws (3) and remove the horizontal timing belt cover (2).
Unscrew the screw (4) and remove the vertical timing belt outer cover (1).
Removal of the timing system assembly
Loosen the positioning screw (20) of the tensioner pulley (21) of the horizontal cylinder timing belt.
Loosen the screw (27) securing the tensioner pulley of the horizontal cylinder timing belt and move the tensioner pulley (21) to the rest position.
Remove the horizontal cylinder timing belt (9).
Repeat the above operations to remove the vertical cylinder timing belt (23).
To remove the camshaft pulleys, install the tool 88713.3152 on the pulley to be removed to prevent its rotation, and using service scoket no. 88700.5644 inserted in a torque wrench or ratchet arm, loosen the pulley retaining nut (13).
Remove the nut (13), washer (14) and pulley (16).
Important
On reassembly, always fit new nuts.
Unscrew and remove the idler pulleys (11).
Use the wrench of tool no. 88700.5644 to lock rotation of the drive roller on the crankcase and, using the socket combined with the tool, loosen the nut (6).
Remove the nut (6), the washer (7) and the outer pulley (8).
Remove the first Woodruff key (24) located on the timing belt driveshaft.
Remove the intermediate spacer (10) and the inner pulley (22).
Remove the secondt Woodruff key (26) located on the timing belt driveshaft.
Remove the spacer (5) and the circlip (25).
Disassembly and reassembly of the timing belt pulleys
To disassemble the pulleys, loosen and remove the three screws (12), slide of the washer and (15) and remove the pulley (16) from the flange (17).
To reassemble, fit the pulley (16) on the hub (17), aligning the timing mark (G) on the pulley with the timing mark on the (H) on the hub.
Fit the washer (15) against the pulley, aligning the timing notch (I) with the timing marks (G) and (H) on the pulley and the hub respectively.
Insert the three screws (12) in the threaded holes (L) of the hub.
Refitting the timing system assembly
Refitting the camshaft timing pulleys
Check that the keyway on the end of camshaft is in good condition and without burrs.
Fit one key (C) into the camshaft keyway.
Important
During reassembly, take care that the timing mark “D” on the spacer flange is aligned with the mark “A” on the pulley and washer.
Fit the assembled pulley (16) onto the camshaft, so that is firmly seated.
Warning
Make sure that the Woodruff key is not dislodged.
Insert tool no. 88713.3152 in the belt pulleys to prevent their rotation.
Apply a smear of grease to the thread and underside of the ringnut (13), and fit the washer (14) and the ringnut.
Important
Always fit new nuts on reassembly.
Using the socket of service tool no. 88700.5644 in combination with a torque wrench, tighten the nuts (13) to their specified torque (Sect. C 3 Engine torque settings).
Refitting the timing belt driveshaft pulleys
Install the circlip (25) on the pulley side of the timing belt driveshaft. Drive it into its seat using the protective cap 88700.5749 and the relative drift.
Fit the spacer (5) with the slot facing the crankcase.
Locate on the timing belt drievshaft, the first Woodruff key (26), the inner pulley (22) the intermediate spacer (10) and the second Woodruff key (24).
Then fit the outer pulley (8) the outer spacer (7) lock nut (6).
Important
To prevent the nuts working loose and consequent serious engine damage, always use new self-locking nuts on all the timing belt pulleys on reassembly.
Notes
Apply a thin coating of grease to the thread and underside of the nut (6).
Use the wrench of tool 88700.5644 to restrain the pulleys against rotation and, using the bush of the tool in a torque wrench, tighten the self-locking nut to the specified torque (Sect. C 3, Engine torque settings).
Refitting the timing belt tensioner pulleys
If removed, apply the recommended threadlocker to the idler pulley (11) and tighten to the specified torque (Sect. C 3, Engine torque settings).
Position the crankshaft so that the piston of the horizontal cylinder is at TDC of its power stroke. This is achieved by aligning the timing mark (A) on the timing belt driveshaft pulley (8) with the reference notch (D) on the crankcase cover.
Important
Turn the timing belt driveshaft pulley with the spark plugs removed from the engine.
Remove the inspection cover (C) from alternator-side crankcase cover by unscrewing the two screws (D).
Install the service tool 88713.2011 in the alternator-side crankcase cover to hold the crankshaft against rotation and secure it with the relative pin.
Remove the srew (F) from the inner timing belt cover (E) and recover the washer.
Restrain the camshafts of both cylinder heads by screwing tool no. 88713.2282 into the camshaft end caps.
Turn the pulleys by hand until the end of the tool engages the slot in the camshaft.
Fit the horizontal (9) and vertical (23) timing belts using your hands only and without altering the alignment of the pulleys.
Locate the tensioner pulleys (21) on the vertical and horizontal cylinders. Screw in, but do not tighten at this point, the screws (27) and (20), so that the tensioner pulleys can rotate.
Check the timing belt tension and adjust if necessary as described in the paragraph “Measuring timing belt tension” (Sect. D 5).
Warning
Check the tension values on sections of belts (M) and (N) shown in the figure.
When the correct belt tensioning value is reached, ensure that bolts (20), (27) and (12) are tightened to the specified torque (Sect. C 3, Engine torque settings).
Warning
Whenever you renew any components of the timing system, it is good practice to also check the timing (Sect. N 4.1, Cylinder head assemblies: checks and adjustments).
Remove the service tools no. 88713.2282 from the camshaft end caps (E) and refit the screws (F) with the washers, tightening them to the specified torque (Sect. C 3, Engine torque settings).
Remove the crankshaft locking tool 88713.2011 unscrewing first the pin and then the screw from the tool.
Refit the inspection cover (C) in the alternator-side crankcase cover, inserting the two screws (D).
Tighten the screws to the specified torque (Sect. C 3, Engine torque settings).
Notes
Before refitting the cover (C), check the condition of the O-ring and renew it if necessary.
Refitting the timing belt covers
Position the vertical timing belt cover (1) on the engine.
Fit the cover retaining screws (4) and tighten to the specified torque (Sect. C 3, Engine torque settings).
Locate the horizontal timing belt cover (2) on the engine.
Tighten the screws (4) and (3) to the specified torque (Sect. C 3, Engine torque settings).

Operation | Section reference
Remove the horizontal cylinder exhaust pipe | L 8, Refitting the exhaust system
Refit the fuel tank | L 2, Refitting the fuel tank

N