User Guide

11.34
11 25 050 Removing piston
•
Remove piston pin circlips.
•
Press out piston pin with
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.
Determining clearance of piston in cyl-
inder
•
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”
•
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)
E110150
2
1
3
E110160
B
S