Inspecting The Piston - Gilera Nexus 500 Workshop Manual

Engine
- Calculate the piston pin coupling clearance.
N.B.
THE PIN HOUSINGS HAVE 2 LUBRICATION
CHANNELS. FOR THIS REASON, MEASURE-
MENT MUST BE MADE ACCORDING TO THE
PISTON AXIS.
Characteristic
Standard clearance:
0.001 ÷ 0.010 mm

Inspecting the piston

- Measure the outside diameter of the piston, per-
pendicular to the gudgeon pin axis.
- Take the measurement in the position shown in
the figure.
Characteristic
A =
43.2 mm
Piston diameter:
92 mm
- Using a bore meter, measure the inner cylinder
diameter at three different points according to the
directions shown in the figure.
Characteristic
Standard diameter:
92 + 0.018 +0.010 mm
- Check that coating is free from flakes.
- Check that the head matching surface exhibits no deformations or wear.
Characteristic
Maximum allowable run-out:
0.05 mm
- Pistons and cylinders are classified into categories based on their diameter. The coupling is carried
out in pairs (A-A, B-B, C-C, D-D).
ENG - 60
Nexus 500