Belarus 1523, Operating Manual

Page: 293 / 312

BELARUS- 1523/1523В /1523.3 /1523В.3 Appendices
282
PECULIARITIES OF DISASSEMBLING AND REASSEMBLING THE ENGINE
When dismantling the engine, remove
the pistons assembled with the
connecting rods upwards only. Prior to
removal, descale the upper part of the
cylinder sleeve.
When replacing the parts of the sleeve-
and-piston assembly and crank
mechanism, pay special attention to
their dimensional groups.
The cylinder sleeves and pistons are
sorted out by their inner and skirt outer
diameters, respectively, into three
dim ensional groups (Б – large, С –
medium, М – small).
The group designation is marked on the
upper sleeve shoulder and the piston
crown.
Group
marking
Cylinder sleeve
diameter, mm
Piston skirt
diameter, mm
Б (large)
06 . 0
04 . 0
110 +
+
05 . 0
07 . 0
110 −
−
С
(medium)
04 . 0
02 . 0
110
+
+
07 . 0
09 . 0
110
−
−
М (small)
02 . 0
110
+
09 . 0
11 . 0
110 −
−
Choose the pistons, connecting-rods
and piston pins of the same weight
group in a set for the engine; the
difference of connecting-rod weights
assembled with pistons shall not exceed
30 g.
The crankshaft and crankpin necks and
crankshaft bearing liners are
manufactured in two nominal sizes, as
follows:
Liner nominal
designation
Shaft neck diameter, mm
main connecting rod
1Н
085 . 0
104 . 0
25 . 85 −
−
100 . 0
119 . 0
00 . 73 −
−
2Н
085 . 0
104 . 0
00 . 85 −
−
100 . 0
119 . 0
75 . 72 −
−
The crankshafts, the crankshaft and
crankpin necks of which are
manufactured to the second nominal
size, bear the following additional
designation of the first web:
“2K” – crankshaft necks of the
second nominal size;
“
2Ш ” – crankpin necks of the second
nominal size;
“2K
Ш ” – crankshaft and crankpin
necks of the second nominal size.