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Cylinder, piston
Assembly
1. Gently pull out the cylinder, and hold the piston and connecting rod with your hands;
2. Remove the piston pin retaining ring with needle-nose pliers, push the piston pin out of the small head hole
of the connecting rod, and remove the piston (note: prevent the piston pin retaining ring from falling into the
box);
3. Remove the cylinder block box gasket.
Remarks:
①the piston is
turned to the top dead center before disassembly.
②do not drop the timing chain into the crankcase.
③ when the cylinder is pulled out of the piston, fix the piston and connecting rod by hand or other auxiliary tools to avoid
collision with the box and cause damage.
Inspection
1. Check the cylinder inner wall and piston skirt:if there are obvious scratches or wear on the inner wall of the
cylinder and the piston skirt, the defective parts must be replaced;
2. Check whether the three piston rings are abnormally worn ( if there is abnormal wear , the corresponding parts need to be
replaced ).
Disassemble the piston ring
1. Remove the combination of the first air ring, the second air ring and the oil ring.
Tip: To remove the piston ring, open the end notch by hand and lift the other side of the ring over the top of the piston.
Install the piston ring
1. Remove the carbon deposits on the piston ring groove and the piston ring, and apply an appropriate amount of engine oil to
the piston ring groove;
2. Put the oil ring assembly into the piston oil ring groove.
Remarks:
① do not use the first air ring and the second air ring interchangeably.
②when installing the gas ring, the side with the marked face faces up (piston top).
③installing the oil ring assembly, first install the wave
-shaped lining ring (the arc of the end surface of the wave-shaped
lining ring faces downward), then install the lower side scraper ring, and finally install the side scraper ring.
④ the notch " a " of the first ring is on the left side of the "
△
" ex mark, along the axial direction of the piston pin; the notch "
b " of the second ring is on the right side of the "
△
" ex mark, and the angle with " a " is 180 °; the lower side the notch " e " of
oil ring scraper is at 45 ° between "
△
" ex and " b " ; the angle between " c " and " e " of upper oil ring scraper is 180 °; the
2R/RN marking
id
piston skirt