51601-ZW4-H04 Honda SEE PART DETAILS - PRI; SHOCK ABSORBER ASSY. (Honda Code 8755183).

Fig. 1-Connecting Rod Bearing Measurement
Fig. 2-Connecting Rod Bore I.D.
Fig. 3-Oil ClearanceConnecting rod bearing to crankshaft oil clearance (new) Fig. 3 ... 0.001 to 0.005 inch(0.025 to 0.127 mm)Connecting rod bearing to crankshaft oil clearance (maximum) (Fig. 3) ... 0.006 inch(0.152 mm)Mark pistons for re-installation in same bore from which they are removed.Push pistons out top of the cylinder liners.Repair
Pistons
See Group 0404 for piston-to-cylinder liner measurements.Remove piston rings. IMPORTANT: Do not soak pistons more than 60 minutes.
Avoid contact of solution with skin or eyes.
Soak pistons in 50 percent solution of "Mr. Clean" (or equivalent) and water for 30 to 60 minutes. IMPORTANT: Never clean pistons with wire brush or abrasives.Scrub piston with stiff bristle brush.Rinse pistons in clean water and dry with clean towels. Two different types of pistons marked "B" and "H" on their top face can be selectively installed on 3179D, 4239 D & T, and 6359 D & T engines for a better dead space control inside the cylinder. The difference between the two pistons is 0.006 inch (0.15 mm) on the distance between the piston pin center and the piston top.When replacing pistons, install pistons of the same type as the original.When replacing cylinder block or when mark on piston is no longer visible, determine piston type as follows using gauge KCD-10003.Install cylinder liners and crankshaft with bearings in cylinder block.Secure cylinder liners, using cap screws and washers.Install a "B" type piston with its connecting rod and secure with cap.
Fig. 3A-Determining Type of Piston Using Gauge KCD-10003Place gauge KCD-10003 on liner flange and press downward (3A).Turn crankshaft until piston is in "TDC" position.When piston lightly touches gauge then use "B" type pistons.When pisotn does not contact gauge, then use "H" type pistons.If no gauge is available, proceed as follows:Install a "B" type piston with its connecting rod and secure with cap.Using a dial indicator measure protrusion of each piston (at TDC) above face of cylinder block. Measure at cylinder block centerlineInstall a "B" type piston if protrusion is above or equal to 0.004 in. (0.1 mm) and an "H" type piston if protrusion is below 0.004 in. (0.1 mm). IMPORTANT: Maximum allowable piston standout is 0.012 in. (0.30 mm).Piston Rings and Ring Grooves
Do not re-use piston rings.
Fig. 4-JDE-62 Ring Groove Wear GaugeUsing JDE-62 Ring Groove Wear Gauge (Fig. 4), measure top ring groove. If gauge shoulders contact the ring land, groove is excessively worn.Measure rectangular ring grooves with proper new ring and a feeler gauge.
Fig. 5-Measure Ring GroovesRing groove clearance (maximum) (Fig. 5) ... 0.008 inch(0.20 mm)Piston Pin Bore
Fig. 6-Piston Pin AssemblyPiston pins must fit piston pin bore with a thumb press fit (Fig. 6).Replace piston if piston pin bore is worn.Piston Pin Bushing
Fig. 7-Piston PinMeasure piston pin bushing inside diameter (Fig. 8) with bushing in connecting rod.Piston pin bushing size; If piston pin size is not within specifications, install a new one.Piston Pin Bushing
Fig. 8-Piston Pin BushingMeasure piston pin bushing inside diameter (Fig. 8) with bushing in connecting rod.Piston pin bushing size; Check piston pin size (Group 0403, above).Find the difference, piston pin/bushing clearance, between the piston pin size and the bushing size. The clearance (Fig. 9) must be 0.0008 to 0.0022 in. (0.02 to 0.06 mm).
Fig. 9-Piston Pin/Bushing ClearanceIf bushing size is not within specifications, install a new one.
Fig. 10-Bushing Remover and InstallerUsing the bushing remover and installer listed below, push bushing out of connecting rod (Fig. 10). IMPORTANT: Be sure oil hole in connecting rod (1, Fig. 11) and oil hole in bushing (2) are aligned.
Fig. 11-Oil HoleUsing the bushing remover and installer (Fig. 10), push bushing into connecting rod until one side is flush with connecting rod.Hone bushing to size shown above under "Inside Diameter".Installation
Fig. 12-Piston and Rod "Front"Assemble pistons and connecting rods, making sure the word "FRONT" on top of the piston and side of connecting rod are on same side (Fig. 12).Coat piston pin with a film of engine oil and insert into piston pin bore. Install new piston pin snap rings. Check to be sure snap rings are seated in grooves of piston pin bore. IMPORTANT: Incorrect size ring expander will damage rings.
Fig. 13-JDE-45 or JDE-85 Piston Ring Expander (JDE-135 Not Shown)Use correct piston ring expander for your engine (Fig. 13). New rings are furnished with correct end gap; therefore, fitting ring to the liner is not necessary.
Fig. 14-Oil Control RingInstall oil ring expander in bottom ring groove (Fig. 14). Position end gap over either end of piston pin.Install oil control ring in bottom ring groove over ring expander. Install with end gap on opposite side of piston from ring expander gap.
Fig. 15-Piston Ring Pip MarksRectangular compression ring has two pip marks (Fig. 15) or the word "TOP" on one side. Install rectangular compression ring in center ring groove with pip mark or word "TOP" toward top of piston.Position gap in rectangular compression ring on opposite side of piston from oil control ring gap.
Fig. 16-Keystone Compression RingKeystone compression ring (Fig. 16) has one pip mark or the word "TOP" on one side. Install keystone compression ring in top ring groove with pip mark or word "TOP" toward top of piston.Position gap in Keystone compression ring on opposite side of piston from rectangular compression ring gap. IMPORTANT: Do not install piston assemblies in cylinder liners until the liners have been properly prepared. See Group 0404 for preparation information.Make sure cylinder liners are fastened down. Put engine oil on piston rings and on cylinder liner walls.
Fig. 17-JD-271 or JDE-84 Piston Ring CompressorUse correct piston ring compressor (Fig. 17) for your engine: Position ring compressor on top of cylinder liner.Insert piston, with "FRONT" to the front of engine, in ring compressor.Push pistons into cylinder liners.