- 21 -
KD 477-2 Workshop Manual_cod. ED0053029370_
1° ed
_ rev.
00
X
17
18
19
0,30
÷
0,50
0,25
÷
0,50
0,80
0,80
A = 0,22
B -C= 0,18
D = 0,16
0,001
÷
0,010
0,060
Piston rings - Pistons - Piston pins
Check the wear of piston rings by fitting them into the cylinder throu-
gh the lower end and measuring the end gap (fig.17). The values
should be:
Check that the rings move freely in the grooves and check the ring/
groove clearance using a feeler gauge (fig.18).
If the clearance exceeds the values shown in the table, renew the pi-
ston and the piston rings.
Piston rings must always be renewed after dismantling the
piston.
Piston diameter check: The diameter of the piston must be measured
at approximately 18 mm from the base (fig.19).
Fitting mm
Max. wear mm
Piston ring
1
st
Compression
2
nd
- 3
rd
Compression
4
th
Oil scrapper
Max. wear mm
Engine
Diameter mm
Fitting mm
Max. wear mm
Piston ring
Compression
Oil scrapper
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:
CHECKS AND OVERHAUL
KD477-2
89,919 ÷ 89,930
