50539-ZW4-H10 Honda SPACER (19.4X6) (Honda Code 7459530).

1. Remove suction pipe (2) and support (1) from the engine as a unit.2. Remove the ring of carbon from the top inner surface of the cylinders with tool (A).3. Turn the crankshaft until two pistons are at bottom center. 4. Remove connecting rod caps (3) from the two connecting rods.
Do not let the connecting rods hit the bottom edge of the cylinder bores or the crankshaft during removal and installation of the pistons.
5. Push the piston and connecting rod away from the crankshaft until the piston rings are above the cylinder block. 6. Remove the two pistons (4) and the connecting rods. Keep each connecting rod cap with its respective connecting rod and piston. Put identification on each connecting rod as to its location for use at assembly.7. Do Steps 3 through 6 for the remainder of the pistons.Install Pistons
1. Turn the crankshaft until the bearing journal for the pistons to be installed is at bottom center.2. Put clean engine oil on the crankshaft bearing journal and inside of the cylinder walls. Put clean engine oil on the piston rings and connecting rod bearings. 3. Make sure the ring gaps are approximately 120° apart. Install tool (A) on the piston.4. Put the piston in position in the same cylinder bore from which it was removed. The hole (crater) in the top of the piston must be toward (nearest) the center of the engine.5. Push the piston into place while putting the connecting rod into position on the crankshaft.6. Put clean engine oil on the threads of the bolts and contact surfaces of the nuts for the connecting rod caps.
When installing connecting rod caps, make sure that the numbers on the side of the cap is next to and respective with the number on the side of the connecting rod.
7. Put the cap in position on the connecting rod and install the nuts. Tighten the nuts to a torque of 30 3 lb.ft. (4.1 0.4 mkg). Put a mark on each nut and the end of each bolt. Tighten the nuts 60 5° more.8. Follow the same above procedure for installation of the remainder of the pistons.9. Install the suction pipe and support as a unit.end by: a) install oil panb) install cylinder headsDisassemble Pistons
start by: a) remove pistons 1. Remove the rings from the piston with tool (A). 2. Remove snap ring (2), pin (1), and connecting rod (3) from the piston.Assemble Pistons
1. Install connecting rod (1) in the piston with boss (2) on the same side as the hole (crater) in the top of the piston.2. Install piston pin (3) and snap ring (4). 3. When old pistons are to be used, clean the piston grooves with tool (A).4. Install the spring for the oil ring. Install the oil ring with tool (B). The gap in the ring must be approximately 180° from the oil ring spring connection.5. Install the compression ring using tool (B). The side of the ring having identification "TOP" must be toward top of piston. The gaps in the rings must be approximately 120° apart. Compression rings not having identification must be installed with the edge having a bevel toward the top of the piston.end by: a) install pistons