Inspecting The Small End; Inspecting The Wrist Pin - PIAGGIO XEVO 125 Euro 3 Service Station Manual

XEVO 125 Euro 3

Inspecting the small end

- Measure the internal diameter of the rod small
end using an internal micrometer.
N.B.
REPLACE THE CRANKSHAFT IF THE DIAME-
TER OF THE ROD SMALL END EXCEEDS THE
STANDARD DIAMETER OR IT SHOWS SIGNS
OF WEAR OR OVERHEATING.
Characteristic
Rod small end check-up: Maximum diameter
15.030 mm
Rod small end check-up: Standard diameter
15 +0.015+0.025 mm

Inspecting the wrist pin

- Measure the outer diameter of the gudgeon pin.
- Calculate the coupling clearance between pin
and connecting rod end.
- Measure the capacity diameter on the piston.
- Calculate the piston pin coupling clearance.
- Measure the outside diameter of the piston, per-
pendicular to the gudgeon pin axis.
- Carry out the measurement as shown in the fig-
ure.
41.1 mm (from the crown)
- Using a bore meter, measure the inner cylinder
diameter at three different points according to the
directions shown in the figure.
- Check that the head matching surface exhibits no
deformations or wear.
Maximum admissible displacement: 0.05 mm
- Pistons and cylinders are classified according to
diameter (0.2 - 0.4 - 0.6 m). The coupling is carried
out in pairs (A-A, B-B, C-C, D-D).
- The cylinder rectifying operation should be car-
ried out with a surfacing that respects the original
angle.
Engine
ENG - 31