11 25 050 Removing piston Determining clearance of piston in cyl- inder • Remove piston pin circlips. • Press out piston pin with • Measure cylinder bore at distance of 55...65 mm (2.17...2.56 in) from the upper edge with an inter- nal micrometer at three points (1, 2, 3). • Make a note of the largest value as dimension “ A ” E110160 • Measure piston diameter “ B ” at distance H = 16 mm (0.63 in) from the lower edge at a right angle to the piston pin axis. L Note: Determine piston clearance: Dimension “ A ” minus dimension “ B ” = piston clear- ance Piston clearance: When new ................. 0.024...0.040 mm (0.0094...0.00157 in) Wear limit ......................max.
0.100 mm (0.0039 in) 11.34 drift, BMW No. 11 6 581. L Note: Mark exhaust-valve side on piston crown. 11 25 671 Disassembling piston • Remove piston rings with piston ring pliers. • Carefully clean piston. • Check piston for signs of damage. 1 2 3 E110150 1 2 3 B S