PISTON, PISTON RING, PISTON PIN INSPECTION

1. Measure the piston outer diameter using a micrometer.The measurement position is ZJ: 8.7—12.7 mm {0.35—0.50 in}, ZY and Z6: 8.5—12.5 mm{0.34—0.49 in}from the lower end of the piston, and in the thrust direction.

Piston outer diameter

ZJ: 73.970—74.004 mm {2.9122—2.9135 in}

ZY: 77.970—78.004 mm {3.0697—3.0710 in}

Z6: 77.970—77.980 mm {3.0697—3.0700 in}

2. Calculate the piston-to-cylinder clearance from the cylinder bore inner diameter and the piston outer diameter.

Standard clearance

-0.004—0.043 mm {-0.0002—0.0169 in}

Maximum clearance

ZJ: 0.065 mm {0.0026 in}

ZY: 0.070 mm {0.0028 in}

Z6: 0.090 mm {0.0035 in}

3. Measure the piston-to-ring groove clearance around the entire circumference using a feeler gauge.

Standard clearance

Top: 0.030—0.065 mm {0.0012—0.0025 in}

Second: 0.03—0.07 mm {0.0012—0.0027 in}

Oil: 0.04—0.15 mm {0.0016—0.0059 in}

Maximum clearance

Top, Second: 0.15 mm {0.0059 in}

Oil: 0.20 mm {0.0078 in}

Standard end gap

Piston ring	ZJ	ZY, Z6
Top	0.13—0.23 mm {0.006—0.009 in}	0.14—0.24 mm {0.006—0.009 in}
Second	0.23—0.50 mm {0.010—0.019 in}	0.24—0.39 mm {0.010—0.015 in}
Oil (rail)	0.10—0.70 mm {0.004—0.027 in}

Maximum end gap

1.0 mm {0.039 in}

5. Measure the piston pin hole diameter. Measurement positions total eight and they are in the X and Y directions at four points (A, B, C, and D) as shown in the figure.

Standard inner diameter

ZJ: 17.988—18.000 mm {0.7082—0.7086 in}

ZY, Z6: 18.988—19.000 mm {0.7476—0.7480 in}

6. Measure the piston pin outer diameter using a micrometer. Measurement positions total eight and they are in the X and Y directions at the four points (A, B, C, and D) as shown in the figure.

Standard outer diameter

ZJ: 17.974—17.980 mm {0.7077—0.7078 in}

ZY, Z6: 18.974—18.980 mm {0.7471—0.7472 in}

7. Calculate the clearance between the piston pin hole diameter and the piston pin outer diameter.