POWR Power unit5-49 69J3D11Checking the piston ring grooves1. Measure the piston ring grooves.Replace the piston if out of specification.Checking the piston ring sideclearance1. Measure the piston ring side clearance.Replace the piston and piston rings as aset if out of specification.Checking the piston pin boss bore1. Measure the piston pin boss bore.Replace the piston if out of specification.Piston ring end gap d:Top ring:0.15–0.30 mm(0.0059–0.0118 in)Second ring:0.30–0.45 mm(0.0118–0.0177 in)Oil ring:0.15–0.60 mm(0.0059–0.0236 in)Measuring point e: 20 mm (0.8 in)Piston ring groove:Top ring a:1.23–1.25 mm (0.048–0.049 in)Second ring b:1.22–1.24 mm (0.048–0.049 in)Oil ring c:2.51–2.53 mm (0.099–0.100 in)Piston ring side clearance:Top ring a:0.04–0.08 mm(0.0016–0.0031 in)Second ring b:0.03–0.07 mm(0.0012–0.0027 in)Oil ring c:0.04–0.13 mm(0.0016–0.0051 in)Piston pin boss bore:21.02–21.03 mm(0.8276–0.8280 in)
