Piston Ring Replacement

Remove the piston from the engine block (see CRANKSHAFT AND PISTON REMOVAL ).
Using a ring expander (A), remove the old piston rings (B).

Fig 1: Installing Ring Expander And Piston Rings
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Clean all ring grooves thoroughly with a squared-off broken ring or a ring groove cleaner with a blade to fit the piston grooves.
The top and second ring grooves are 1.2 mm (0.047 in) wide. The oil ring groove is 2.0 mm (0.079 in) wide ('08-10 models).

The top ring groove is 1.2 mm (0.047 in) wide. The second ring groove is 1.0 mm (0.039 in) wide. The oil ring groove is 2.0 mm (0.079 in) wide ('11-12 models). File down a blade if necessary.

Do not use a wire brush to clean the ring grooves, or cut the ring grooves deeper with the cleaning tools.

NOTE: If the piston is to be separated from the connecting rod, do not install the new rings yet.
Using a piston that has its rings removed, push a new ring (A) into the cylinder bore 15-20 mm (0.59-0.79 in) from the bottom.

Fig 2: Identifying Ring And Piston Ring End-Gap In Cylinder Bore
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Measure the piston ring end-gap (B) with a feeler gauge:
- If the gap is too small, check to see if you have the proper rings for your engine.
- If the gap is too large, recheck the cylinder bore diameter against the wear limits (see CYLINDER BORE HONING ). If the bore is beyond the service limit, the engine block must be rebored.
  Piston Ring End-Gap ('08-10 models)
  
  Top Ring:
  
  Standard (New): 0.20-0.35 mm (0.0079-0.0138 in)
  
  Service Limit: 0.60 mm (0.0236 in)
  
  Second Ring:
  
  Standard (New): 0.50-0.65 mm (0.0197-0.0256 in)
  
  Service Limit: 0.70 mm (0.0276 in)
  
  Oil Ring:
  
  Standard (New): 0.20-0.70 mm (0.0079-0.0276 in)
  
  Service Limit: 0.75 mm (0.0295 in)
  
  Piston Ring End-Gap ('11-12 models)
  
  Top Ring:
  
  Standard (New): 0.20-0.30 mm (0.0079-0.0118 in)
  
  Service Limit: 0.55 mm (0.0217 in)
  
  Second Ring:
  
  Standard (New): 0.20-0.32 mm (0.0079-0.0126 in)
  
  Service Limit: 0.42 mm (0.0165 in)
  
  Oil Ring:
  
  Standard (New): 0.20-0.50 mm (0.0079-0.0197 in)
  
  Service Limit: 0.55 mm (0.0217 in)
Install the top ring and the second ring as shown. The top ring (A) has a 1R mark, and the second ring (B) has a 2RN mark ('08-10 models) or 2R mark ('11-12 models). The manufacturing marks (C) must face upward.

Fig 3: Installing Top Ring And Second Ring
Courtesy of AMERICAN HONDA MOTOR CO., INC.
After installing a new set of rings, measure the ring-to-groove clearances:
Top Ring Clearance

Standard (New): 0.060-0.085 mm (0.00236-0.00335 in)

Service Limit: 0.13 mm (0.0051 in)

Second Ring Clearance ('08-10 models)

Standard (New): 0.040-0.065 mm (0.00157-0.00256 in)

Service Limit: 0.13(0.0051)

Second Ring Clearance ('11-12 models)

Standard (New): 0.020-0.045 mm (0.00079-0.00177 in)

Service Limit: 0.13 mm (0.0051 in)

Fig 4: Measuring Top Ring Clearance
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Rotate the rings in their grooves to make sure they do not bind.
Position the ring end gaps as shown.

Fig 5: Positioning Ring End Gaps
Courtesy of AMERICAN HONDA MOTOR CO., INC.