Camshaft Inspection

NOTE: Do not rotate the camshaft during inspection.

1.Remove the rocker arm assembly.

2.Put the rocker shaft holders, camshaft and camshaft holders on the cylinder head, then tighten the bolts to the specified torque.

Specified torque:
8 mm bolts: 
22 N·m (2.2 kgf·m, 16 lbf·ft) 
6 mm bolts: 
12 N·m (1.2 kgf·m, 8.7 lbf·ft) 
6 mm bolts: (21), (22), (23) 

 

3.Seat the camshaft by pushing it away from the camshaft pulley end of the cylinder head.

4.Zero the dial indicator against the end of the camshaft, then push the camshaft back and forth and read the end play. If the end play is beyond the service limit, replace the cylinder head and recheck. If it is still beyond the service limit, replace the camshaft.

Camshaft End Play:
Standard (New): 0.05-0.20 mm
(0.002-0.008 in.)
 
Service Limit: 0.4 mm (0.02 in.) 

 

5.Unscrew the camshaft holder bolts two turns at a time, in a crisscross pattern. Then remove the camshaft holders from the cylinder head.

6.Lift the camshafts out of the cylinder head, wipe them clean, then inspect the lift ramps. Replace the camshaft if any lobes are pitted, scored, or excessively worn.

7.Clean the camshaft journal surfaces in the cylinder head, then set the camshafts back in place. Place a plastigage strip across each journal.

8.Install the camshaft holders, then tighten the bolts to the specified torque as shown in step 2.

9.Remove the camshaft holders. Measure the widest portion of plastigage on each journal.

  • If the camshaft-to-holder clearance is within limits, go to 11.
  • If the camshaft-to-holder clearance is beyond the service limit and the camshaft has been replaced, replace the cylinder head.
  • If the camshaft-to-holder clearance is beyond the service limit and the camshaft has not been replaced, go to 10.

Camshaft-to-Holder Oil Clearance:
Standard (New):  
No. 1 Journal: 0.030-0.069 mm (0.001-0.003 in.) 
No. 2, 3, 4, 5 Journals: 0.060-0.099 mm (0.002-0.004 in.) 
Service Limit: 0.15 mm (0.006 in.) 

 

10.Check the total runout with the camshaft supported on V-blocks.

  • If the total runout of the camshaft is within the service limit, replace the cylinder head.
  • If the total runout is beyond the service limit, replace the camshaft and recheck the camshaft-to-holder oil clearance. If the oil clearance is still beyond the service limit, replace the cylinder head.

Camshaft Total Runout:
Standard (New): 0.03 mm (0.001 in.) max. 
Service Limit: 0.04 mm (0.002 in.) 

 

11.Measure cam lobe height.

Cam Lobe Height Standard (New):
 INTAKE EXHAUST 
PRI 33.925 mm
(1.3356 in.) 
34.092 mm
(1.3422 in.) 
SEC 29.638 mm
(1.1668 in.) 

PRI: Primary SEC: Secondary 
 C/C: Cam Chain