The pistons and cylinders of the engine are divided by size into three groups and are designated 0, 1, and 2. The group number is stamped next to the cylinder on the split surface of the cylinder block, as shown by the arrow in fig. 64. The piston group number must always match the cylinder group number. Piston designation, arrow (points to the front of the engine) and group number are stamped on the piston head.
Pic. 64. Designation of size groups on the cylinder block.
Mark each piston and connecting rod with the number of the cylinder from which they are removed. It is better to do this with paint on the piston head and mark with an arrow the direction towards the front of the engine.
When disassembling the piston, mark the position of the connecting rod cap and the connecting rod, marking them with an arrow and the cylinder number. The designation can be applied with a center punch (1 notch - cylinder No. 1, etc.), as shown in fig. 65.
Pic. 65. Designation of the connecting rod cap and connecting rod before disassembly.
Mark the connecting rod bearings and connecting rod caps accordingly. There is a hole in the connecting rod bushing for supplying oil to the piston pin.
Remove the connecting rod cap and bearing and remove the rest of the parts from the cylinder block as above. If necessary, clean the carbon deposits on the upper belt of the cylinder with a scraper.
Remove the circlips and press out the piston pin with a drift.
Remove piston rings with pliers. If rings are to be reused, they must be marked. In the absence of pliers, metal strips can be used to remove the rings, which are inserted between the piston and the inner surface of the ring. The strip must protrude beyond the edge of the piston head to avoid damage to the cylindrical surface of the piston.