Piston Inspection
PISTON INSPECTIONCaution:
^ The piston and connecting rod cannot be disassembled.
^ When replacing the piston, piston pin, piston ring and connecting rod, replace them together as a single unit.
1. Measure the outer diameter of each piston at right angle 90° to the piston pin, 10.0 mm (0.40 in) above the under of the piston. If not within the specification, replace the piston, piston pin, piston ring and connecting rod as a single unit.
Piston diameter (Standard) 87.465-87.495 mm (3.4435-3.4446 in)
2. Measure the piston-to-cylinder clearance. If not within the specification, replace the piston, piston pin, piston ring and connecting rod as a single unit.
Piston-to-cylinder clearance (Standard) 0.025-0.045 mm (0.0010-0.0017 in)
Piston-to-cylinder clearance (Maximum) 0.11 mm (0.0043 in)
3. Measure the piston ring-to-ring groove clearance around the entire circumference.
^ If it exceeds the specification, replace the piston, piston pin, piston ring and connecting rod as a single unit.
Piston ring-to-ring groove clearance (Standard)
Top: 0.03-0.08 mm (0.0012-0.0031 in)
Second: 0.03-0.07 mm (0.0012-0.0027 in)
Oil: 0.03-0.07 mm (0.0012-0.0027 in)
Piston ring-to-ring groove clearance (Maximum)
Top: 0.17 mm (0.0067 in)
Second, Oil: 0.15 mm (0.0059 in)
4. Insert the piston ring into the cylinder by hand and use the piston to push it to the bottom of the ring travel.
5. Measure each piston ring end gap with a feeler gauge.
^ If it exceeds the specification, replace the piston, piston pin, piston ring and connecting rod as a single unit.
Piston end gap (Standard)
Top: 0.16-0.31 mm (0.0063-0.0122 in)
Second: 0.33-0.48 mm (0.0130-0.0189 in)
Oil (rail): 0.20-0.70 mm (0.0079-0.0275 in)
Piston end gap (Maximum) 1.0 mm (0.0393 in)