PIAGGIO X9 Evolution 500 - Inspecting the Small End

- Remove the piston sealing rings and the oil scra-
per.
CAUTION
NOTE THE ASSEMBLY POSITIONS OF THE LININGS TO
PREVENT INVERTING THE POSITION IN CASE OF REUSE.
N.B.
BE CAREFUL NOT TO DAMAGE THE SEALING RINGS
DURING REMOVAL.
Inspecting the small end
- Using a bore gauge, measure the connecting rod
small end diameter.
N.B.
IF THE CONNECTING ROD SMALL END DIAMETER EX-
CEEDS THE STANDARD DIAMETER, EXHIBITS WEAR OR
OVERHEATING, PROCEED TO REPLACE THE CRANK-
SHAFT AS DESCRIBED IN THE CRANKCASE AND
CRANKSHAFT CHAPTER.
Characteristic
Standard diameter:
22 + 0.025 +0.015 mm
Inspecting the wrist pin
- Check the pin outside diameter using a micrometer.
Characteristic
Standard diameter:
22 0 -0.004 mm
- Calculate the coupling clearance between pin
and connecting rod end.
Characteristic
Standard clearance:
0.015 ÷ 0.029 mm
- Measure the diameter of the bearings on the piston.
Characteristic
Standard diameter:
22 + 0.006 + 0.001 mm
Engine X9 Evolution 500
ENG - 146