TM RACING 250 EN, Руководство по ремонту

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25
10
mm
20
mm
1
2
4
3
5
1
1^
2^
ENGINE DISASSEMBLY
2.8.6 Piston replacement with cylinder to be machined
if the barrel of the cylinder is scratched, it is necessary to lap the barrel
itself.
After processing it is necessary to measure, with an micrometer (1) for
insides, the diameter of the barrel crosswise at 90° first at a distance of 10
mm (0,393 in) from the top of the cylinder and then at a distance of 20 mm
(0,787 in) from the top of the cylinder.
Once the measurement has been carried out, order the piston so that the
cylinder and piston coupling is 0,08 ÷ 0,09 mm (0,0031 ÷ 0,0035 in).
2.8.7 Cylinder replacement
When there is a need to replace the cylinder, the piston must also be re-
placed so that the cylinder and piston are correctly coupled as described
in the previous paragraphs.
2.8.8 Cylinder and piston re-mounting
Check the condition of the roller cage (1), if worn replace and reassemble
on the connecting rod.
Re-mount the piston (2) on the rod, paying attention that the arrow (3)
is positioned towards the exhaust and then insert the pin (4) and relative
lock ring (5).
Check that the rings are positioned as indicated in the "Ring replacement
and mounting" paragraph.
Oil the cylinder barrel with engine oil.