Piston, Piston Ring, Connecting Rod and Cylinder Disassembly and Reassembly
Precautions: General safety (00)
Disassembly
1)Using a piston ring expander, remove two compression rings (1st and 2nd) and oil ring from piston.
2)Remove piston pin from connecting rod as follows.
a)Remove piston pin circlips (1), as shown.
b)Remove piston pin.
Reassembly
NOTICE:
The engine will seize up if it is operated when the parts listed below are not properly lubricated.
Lubricate all the friction surfaces of these parts with engine oil before installing them.
•Cylinder wall
•Piston
•Piston pin
•Piston ring
•Connecting rod small-end bore
•Piston
•Piston pin
•Piston ring
•Connecting rod small-end bore
1)Remove carbon deposits from piston head and ring grooves using a suitable tool.
2)Install piston pin to piston (1) and connecting rod (2) as follows.
a)Apply engine oil to piston pin and piston pin holes in piston and connecting rod.
b)Fit connecting rod as shown in figure.
NOTE:
Position front mark (4) on piston and oil hole (5) of connecting rod at specified position as shown in figure.
c)Insert piston pin to piston and connecting rod.
d)Install new piston pin circlips (3).
NOTE:
Circlip should be installed with its end gap facing as shown in figure. Install so that circlip end gap comes within such range as indicated by arrow (6).
3)Install piston rings to piston noting the following.
•As shown in figure, 1st and 2nd rings have top mark (1) respectively. When installing these piston rings to piston, top mark side of each ring upward.
•1st ring (2) differs from 2nd ring (3) in thickness, shape and color of surface contacting cylinder wall.
Refer to the figure to distinguish 1st ring from 2nd ring.
•When installing oil ring (4), install spacer first and then two rails.
•1st ring (2) differs from 2nd ring (3) in thickness, shape and color of surface contacting cylinder wall.
Refer to the figure to distinguish 1st ring from 2nd ring.
•When installing oil ring (4), install spacer first and then two rails.
4)After installing three rings (1st, 2nd and oil rings), distribute their end gaps as shown in figure.
| “a”: | 45° | 3. | 1st ring end gap |
| 1. | Front mark | 4. | 2nd ring end gap and oil ring spacer gap |
| 2. | Oil ring upper rail gap | 5. | Oil ring lower rail gap |