Valve Clearance: Service and Repair

CAMSHAFT VALVE CLEARANCE

Inspection and Adjustment


INSPECTION

Perform inspection as follows after removal, installation or replacement of camshaft or valve-related parts, or if there is unusual engine conditions regarding valve clearance.
1.Start the engine and warm it up.
2.Stop the engine.
3.Remove rocker cover. Exploded View.
4.Remove splash guard on RH fender protector.
5.Measure the valve clearance with the following procedure:
a.Set No. 1 cylinder at TDC of its compression stroke.





- Rotate crankshaft pulley clockwise and align TDC mark to timing indicator on front cover.
- At the same time, check that both intake and exhaust cam noses of No. 1 cylinder face outside as shown in the figure.
- If they do not face outside, rotate crankshaft pulley once more (360 degrees) and align as shown in the figure.





b.Use a feeler gauge, measure the clearance between valve lifter and camshaft.










- By referring to the figure, measure the valve clearances at locations marked "x" as shown in the table below (locations indicated with black arrow in the figure) with a feeler gauge.
- No. 1 cylinder compression TDC










c.Rotate crankshaft pulley one revolution (360 degrees) and align
TDC mark to timing indicator on front cover.





- By referring to the figure, measure the valve clearance at locations marked "x" as shown in the table below (locations indicated with black arrow in the figure) with a feeler gauge.
- No. 4 cylinder compression TDC





6.If out of standard, perform adjustment. Refer to "ADJUSTMENT".

ADJUSTMENT

- Perform adjustment depending on selected head thickness of valve lifter.
1.Remove camshaft. Exploded View.
2.Remove valve lifters at the locations that are out of the standard.





3.Measure the center thickness of the removed valve lifters with a micrometer (A).
4.Use the equation below to calculate valve lifter thickness for replacement.










- Thickness of new valve lifter (B) can be identified by stamp mark (A) on the reverse side (inside the cylinder).
Stamp mark "788" indicates 7.88 mm (0.3102 in) in thickness.
NOTE:
Available thickness of valve lifter: 26 sizes range 7.88 to 8.38 mm (0.3102 to 0.3299 in) in steps of 0.02
mm (0.0008 in) (when manufactured at factory). [1][2]Camshaft, Engine.
5.Install the selected valve lifter.
6.Install camshaft. Exploded View.
7.Manually rotate crankshaft pulley a few rotations.
8.Check that valve clearances for cold engine are within specifications by referring to the specified values.
Refer to "INSPECTION".
9.Install all removed parts in the reverse order of removal.
10.Warm up the engine, and check for unusual noise and vibration.