6-34 POWER UNIT
Identification of oversize piston / piston ring
Piston
Oversize
I.D. mark
0.50 mm (0.020 in)
0.50
1st & 2nd ring
Oversize
I.D. mark
0.50 mm (0.020 in)
50
Oil ring
Oversize
I.D. mark
0.50 mm (0.020 in)
Red paint
NOTE:
For the oil ring side rail, measure the outer diameter of the rail
to distinguish because there is no I.D. mark.
Piston ring to groove clearance
Measure the clearance after decarboning.
$
09900-20803: Thickness gauge
Standard
: 1st
0.03 – 0.07 mm (0.001 – 0.003 in)
2nd 0.02 – 0.06 mm (0.001 – 0.002 in)
Service limit: 1st
0.12 mm (0.005 in)
2nd 0.10 mm (0.004 in)
If the measurement exceeds the service limit, replace the piston
and/or the piston ring.
Standard:
Piston ring groove width
Piston ring thickness
1.22 – 1.24 mm
1.17 – 1.19 mm
(0.048 – 0.049 in)
(0.046 – 0.047 in)
1.51 – 1.53 mm
1.47 – 1.49 mm
(0.059 – 0.060 in)
(0.058 – 0.059 in)
2.81 – 2.83 mm
———
(0.111 – 0.112 in)
1st
2nd
Oil
$
09900-20102: Vernier calipers
09900-20205: Micrometer
I.D. mark
I.D. mark
1st, 2nd ring
I.D. mark
1st, 2nd ring