Remove valve.
Clean guide bushing.
Measure the inside diameter of the guide bushings at six points.
Measure the diameter of the valve stem at three points with a micrometer.
Subtract the average diameter of the valve stem from the average diameter of the guide sleeve. The result will be the maximum radial clearance.
Maximum allowable radial clearance:
- inlet valve 0.08mm
- outlet valve 0.1mm
If the measured values exceed the permissible values, the guide bushings must be replaced (work of a specialized workshop).