Kohler KD425-2, Workshop Manual

Page: 28 / 56

- 28 -
22
20
21
23
4
A = 0,22
B = 0,18
C = 0,16
0,30 ÷ 0,50
0,80
0,25 ÷ 0,50
0,003 ÷ 0,013 0,050
84,910 ÷ 84,940
KD 425-2
KD 425-2 21,997 ÷ 22,002 0,023 ÷ 0,038 0,070
Checks and overhaul
Fitting mm
Oil scrapper
Max. wear mm
Piston ring
Compression
Max. wear mm Piston ring
1st Compression
2nd Compression
3rd Oil scrapper
Important
• Piston rings must always be renewed after dismantling the
piston.
Engine Diameter mm
Fitting mm Max. wear mm
Piston diameter check: The diameter of the piston must be
measured at approximately 18 mm from the base (fig.22).
Check the clearance between cylinder and piston, if it is greater
than 0.120 mm both cylinder and piston must be replaced.
Assembly clearance between piston pin and piston in
millimetres:
Check that the rings move freely in the grooves and check the
ring/groove clearance using a feeler gauge (fig.21).
If the clearance exceeds the values shown in the table, renew
the piston and the piston rings.
Piston rings - Pistons - Piston pins
Check the wear of piston rings by fitting them into the cylinder
through the lower end and measuring the end gap (fig.20). The
values should be:
Engine
Ø Piston pin
mm
Assy.
clearance
mm
Max wear
mm
Checking parallelism between the two axes of the connecting
rod (fig.23):
1 . Fit the wrist pin in the hole in the small end of the connecting
rod and fit a calibrated pin into the big end (with bush fitted).
Connecting rods
The connection between the connecting rod small end and the
wrist pin is without a bushing. Assembly clearance between
connecting rod small end and piston pin in millimetres:
KD425-2 Workshop Manual_cod. ED0053031750_
1° ed
_ rev.
00