VALVE CLEARANCE MEASUREMENT
Measure the valve clearance as illustrated.
1. Set special tool crankshaft adapter (MB992000) to the crankshaft, and install the crankshaft pulley center bolt and washer.
2. | caution | The crankshaft should always be rotated clockwise. |
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 number 1 cylinder to TDC on the compression stroke.) 3. Make paint marks on three 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. |
4. 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.
5. The valve clearances (arrows) shown in figure are measured.
6. 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 (0.009 ± 0.001 inch)
- Exhaust valve 0.30 ± 0.04 mm (0.012 ± 0.001 inch)
7. 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.
8. 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.
9. 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.
10. Measure the valve clearance at the location shown with an arrow.
11. If the measured value does not conform to the standard value, record the measured value.
12. 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 (0.0008 inch) intervals in the 5.10 - 5.70 mm (0.2008 - 0.2244 inch) range. |
13. 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 tappetB: Thickness of old valve tappet
C: Measured valve clearance
Equation:Intake valve: A = B + [C - 0.22 mm (0.009 in)]
Exhaust valve: A = B + [C - 0.30 mm (0.012 in)]
For removal and installation procedures for the valve tappet, refer to
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