Piston, Ring, Pin, and Connecting Rod Removal and Installation: Removal

Crankshaft - Remove
Oil Jet - Remove

Metal or Hard Carbon - Remove

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1. If you can feel a ridge of metal or hard carbon around the top of each cylinder, remove it with a ridge reamer (A). Follow the reamer manufacturer's instructions. If the ridge is not removed, it may damage the piston as it is pushed out.

Piston/Connecting Rod Assembly - Remove

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1. Use the wooden handle of a hammer (A) to drive out the piston/connecting rod assembly (B). Take care not to damage the cylinder with the connecting rod

2. Reinstall the connecting rod bearings and caps after removing each piston/connecting rod assembly

3. Mark each piston/connecting rod assembly with its cylinder number to make sure they are reused in original order.

NOTE: The existing number on the connecting rod does not indicate its position in the engine, it indicates the rod bore size.

Piston Ring - Remove

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1. Using a ring expander (A), remove the old piston rings (B)

2. Clean all the ring grooves thoroughly with a squared-off broken ring or a ring groove cleaner with a blade to fit the piston grooves. File down the blade, if necessary. The top and second ring grooves are 1.0 mm (0.039 in) wide and the oil ring groove is 2.0 mm (0.079 in) wide. Do not use a wire brush to clean the ring grooves or cut the ring grooves deeper with the cleaning tool.

NOTE: If the piston is to be separated from the connecting rod, do not install new rings yet.

Piston Ring End Gap - Inspect

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2. 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 . If the bore is beyond the service limit, the engine block must be rebored.

Piston Ring End-Gap

Top Ring
Standard (New):
RIKEN:	0.15-0.25 mm (0.006-0.009 in)
TPR:	0.15-0.30 mm (0.006-0.011 in)
Service Limit:	0.60 mm (0.023 in)
Second Ring
Standard (New):	0.30-0.42 mm (0.012-0.016 in)
Service Limit:	0.65 mm (0.025 in)
Oil Ring
Standard (New):
RIKEN:	0.20-0.50 mm (0.008 -0.019 in)
TPR:	0.10-0.40 mm (0.004-0.015 in)
Service Limit:	0.80 mm (0.031 in)

Piston Pin - Remove

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1. Apply new engine oil to the piston pin snap rings (A), and turn them in the ring grooves until the end gaps are lined up with the cutouts in the piston pin bores (B).

NOTE: Take care not to damage the ring grooves.

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2. Remove the snap rings (A) from both sides of each piston. Start at the cutout in the piston pin bore. Remove the snap rings carefully so they do not go flying or get lost. Wear eye protection.

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3. Heat the piston and the connecting rod assembly to about 158°F (70°C), then remove the piston pin.

Piston Pin - Inspect

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1. Measure the diameter of the piston pin.

Piston Pin Diameter

Standard (New):	17.960-17.964 mm (0.70709-0.70724 in)
Service Limit:	17.960 mm (0.70709 in)

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2. Zero the dial indicator (A) to the piston pin diameter.

3. Check the difference between the piston pin diameter and the piston pin hole diameter in the piston.

Piston Pin-to-Piston Clearance

Standard (New):	-0.004-0.003 mm (-0.00016-0.00012 in)
Service Limit:	0.006 mm (0.00024 in)

Courtesy of HONDA, U.S.A., INC.

Courtesy of HONDA, U.S.A., INC.

4. Measure the piston pin-to-connecting rod clearance.

Piston Pin-to-Connecting Rod Clearance

Standard (New):	0.005-0.015 mm (0.00020-0.00059 in)
Service Limit:	0.020 mm (0.00079 in)