Valve Clearance: Adjustments

VALVE CLEARANCE ADJUSTMENT [MZR 2.5]

1. Disconnect the negative battery cable.

2. Remove the plug hole plate. Service and Repair

3. Remove the ignition coils. Service and Repair

4. Remove the spark plugs. Service and Repair

5. Remove the ventilation hose. Service and Repair

6. Disconnect the camshaft position (CMP) sensor connector.

7. Disconnect the oil control valve (OCV) connector.

8. Remove the cylinder head cover. Service and Repair

9. Set the front mudguard (RH) out of the way. Service and Repair

10. Remove the splash shield (RH).

11. Remove the aerodynamic under cover No.2. Aerodynamic Under Cover No. 2 Removal/Installation

12. Remove the drive belt. Service and Repair

13. Remove the engine front cover lower blind plug.






14. Remove the engine front cover upper blind plug.






15. Disconnect the drive shaft (RH) from joint shaft, set the drive shaft (RH) out of the way. (ATX) Drive Shaft Removal/Installation

16. Remove the cylinder block lower blind plug, and install the SST.






17. Rotate the crankshaft in the direction of the engine rotation so that the No.1 piston is at TDC of the compression stroke. (Until the counterweight contacts SST and stops.)

18. Loosen the timing chain using the following procedure.
a. Insert a suitable bolt (M6 X 1.0, length 25-35 mm {0.99-1.3 in}) into the engine front cover upper blind plug and tighten it until it contacts the chain tensioner arm, and then rotate it back one turn. (Set the bolt slightly away from the chain tensioner arm so that it does not contact it.)






b. Using the cast hexagon on the exhaust camshaft, apply force counterclockwise to facilitate unlocking the chain tensioner ratchet.






c. Using a Hex bit socket (2.5 mm {0.098 in}) or T15 Torx bit socket, unlock the chain tensioner ratchet so that it can be lifted up.






d. Using the cast hexagon on the exhaust camshaft, apply force in the direction of the engine rotation to increase tension on the chain.






NOTE:
- The chain tensioner rack is compressed using the chain tension generated by applying force to the exhaust camshaft in the direction of the engine rotation.






NOTE:
- The racket has not been unlocked if the bolt cannot be pressed in approx. 5 mm {0.2 in}.

e. Screw in the bolt set in Step 1 approx. 5 mm {0.2 in} and secure the tensioner arm with the rack compressed.






- If the tensioner arm cannot be secured, return the bolt to its original position and repeat the procedure from Step (3).

19. Fix the exhaust camshaft using a wrench on the cast hexagon, and loosen the camshaft sprocket bolt.






CAUTION:
- Perform the work carefully so that the washer does not drop out.

20. Remove the exhaust camshaft sprocket bolt, exhaust camshaft sprocket, and washer as a single unit.






21. Remove the OCV. Oil Control Valve (OCV) Removal/Installation

NOTE:
- The camshaft caps are to be kept ordered for correct reassembly in their original positions. Do not mix the caps.

22. Loosen the camshaft cap bolts in two or three steps in the order shown in the figure and remove the camshaft cap.






23. Remove the camshafts for the intake and exhaust sides.

24. Remove the tappet.

25. Install an appropriate tappet based on the results of the valve clearance inspection.

- Selected tappet = Removed tappet thickness + Measured valve clearance - Standard valve clearance

Valve clearance [Engine cold]
- IN: 0.22-0.28 mm {0.009-0.011 in}
- EX: 0.27-0.33 mm {0.011-0.012 in}

26. Verify that No.1 cylinder is at TDC of the compression stroke. (Position counterweight contacts SST.)

27. Apply the gear oil (SAE No.90 or equivalent) to each journal of the cylinder head as shown in the figure.






28. With No.1 cylinder cam aligned at TDC of the compression stroke, install the variable valve timing actuator and the camshaft on the intake air side as a single unit.

29. Apply the gear oil (SAE No.90 or equivalent) to each journal of the camshaft as shown in the figure.






30. Temporarily tighten the camshaft cap bolts evenly in 2-3 steps.

31. Tighten the camshaft cap bolts in the order shown in the following two steps.






Tightening procedure
- 5.0-9.0 Nm {51-91 kgf-cm, 45-79 in-lbf}
- 14-17 Nm {1.5-1.7 kgf-m, 11-12 ft-lbf

32. Install the OCV. Oil Control Valve (OCV) Removal/Installation

CAUTION:
- Install a washer to the fourth or fifth thread of the exhaust camshaft sprocket bolt being careful not to drop the washer.
- Do not tighten the camshaft sprocket bolt at this stage. Verify the valve timing before performing the bolt tightening.

33. Install the exhaust camshaft sprocket bolt, exhaust camshaft sprocket, and a new washer as a single unit.






34. Install the SST on the camshaft as shown in the figure.






35. Remove the installation bolt for the engine front cover upper blind plug (M6 X 1.0 length 25-35mm {1.0-1.3 in}), and apply tension to the timing chain.

36. Fix the exhaust camshaft using a wrench on the cast hexagon, and tighten the sprocket bolt.






Tightening torque
- 69-75 Nm {7.1-7.6 kgf-m, 51-55 ft-lbf}

37. Remove the SST from the camshaft.

38. Remove the SST installed in the cylinder block lower blind plug hole.

39. Rotate the crankshaft clockwise two turns and inspect the valve timing.

- If not aligned, loosen the camshaft sprocket bolt and repeat the procedure from Step 34.

40. Install the cylinder block lower blind plug.






Tightening torque
- 18-22 Nm {1.9-2.2 kgf-m, 14-16 ft-lbf}

41. Connect the drive shaft (RH) to joint shaft. (ATX) Drive Shaft Removal/Installation

42. Apply the silicone sealant and install the engine front cover upper blind plug.






CAUTION:
- Install the engine front cover upper blind plug before the applied silicone sealant starts to harden.

Tightening torque
- 8-11 Nm {82-117 kgf-cm, 71-101 in-lbf}

43. Install a new engine front cover lower blind plug.






Tightening torque
- 10-14 Nm {102-142 kgf-cm, 89-123 in-lbf}

44. Install the drive belt. (See Service and Repair.)

45. Install the aerodynamic under cover No.2. Aerodynamic Under Cover No. 2 Removal/Installation

46. Install the splash shield (RH).

47. Install the front mudguard (RH). Service and Repair

48. Install the cylinder head cover. (See Service and Repair.)

49. Connect the OCV connector.

50. Connect the CMP sensor connector.

51. Install the ventilation hose. Service and Repair

52. Install the spark plugs. Service and Repair

53. Install the ignition coils. Service and Repair

54. Install the plug hole plate. Service and Repair

55. Connect the negative battery cable.