INSPECTION

VALVE CLEARANCE MEASUREMENT

Measure the valve clearance as illustrated.

Set the special tool Crankshaft adapter (MB992000) to the crankshaft, and install the crankshaft pulley bolt and washer.

caution

The crankshaft should always be rotated clockwise.

1.Rotate the crankshaft clockwise until the mark on the camshaft sprocket exhaust is aligned with the mark on the upper surface of cylinder head. (Set the No. 1 cylinder to TDC on the compression stroke.)

2.Make paint marks on 3 places at the camshaft sprocket exhaust by means of the following procedure as shown in Figure.
(1) Make a paint mark on the place of 65 degree angle (6.5th tooth) in the counterclockwise direction of the timing mark.
(2) Moreover, make a paint mark on the place of 120 degree angle (12th tooth).
(3) Also, make a paint mark on the place of 120 degree angle (12th tooth).

note

The space between the teeth of the camshaft sprocket exhaust is 10 degree angle.

3.Turn the crankshaft clockwise and locate the paint mark of the camshaft sprocket exhaust on the upper surface of the cylinder head as shown in Figure.

4.The valve clearances (Arrows) shown in Figure are measured.

5.Using a thickness gauge, measure the clearance between the cam base circle and the valve tappet.
If the measured value does not conform to the standard value, record the measured value.
Standard value (cold engine):
Intake valve 0.22 ± 0.04 mm
Exhaust valve 0.30 ± 0.04 mm

6.Turn the crankshaft clockwise and locate the paint mark of the camshaft sprocket exhaust on the upper surface of the cylinder head as shown in Figure.

7.Measure the valve clearance at the location shown with an arrow.
If the measured value does not conform to the standard value, record the measured value.

8.Turn the crankshaft clockwise and locate the paint mark of the camshaft sprocket exhaust on the upper surface of the cylinder head as shown in Figure.

9.Measure the valve clearance at the location shown with an arrow.
10.If the measured value does not conform to the standard value, record the measured value.
11.Replace the valve tappet for the valve whose clearance is out of the standard value.

note

Valve tappets are available in 31 sizes, at 0.02 mm intervals in the 2.70 - 3.30 mm range.

12.Valve tappets should be selected in the following manner.
(1) Remove the valve tappet and measure its thickness.
(2) Calculate the correct thickness for a new valve tappet as follows that achieves the standard valve clearance.
A: Thickness of new valve tappet
B: Thickness of old valve tappet
C: Measured valve clearance
Equation:
Intake valve A = B + (C - 0.22 mm)
Exhaust valve A = B + (C - 0.30 mm)
For removal and installation procedures for the valve tappet, refer to "CAMSHAFT REMOVAL AND INSTALLATION."
(Refer to Camshaft Removal and Installation.

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