PIAGGIO PORTER 1.3 16V 2008, Service Manual

Page: 311 / 892

measured value is considered to be the
cylinder diameter.
Characteristic
Cylinder diameter (standard)
76.000 - 76.030
Cylinder diameter (OS/0.25)
76.250 - 76.280
•
Cylinder scale removal
If scales are formed in the upper part of the cylin-
der holes, a special reamer is necessary to remove
them.
Cylinder reaming
1. Cylinder diameter measurement
Measure the diameter at a point that is 45 mm
away from the upper surface of the cylinder, in the
direction shown in the figure.
If the measured value exceeds 76.28 mm, replace
the cylinder block.
2. Determining the cylinder finishing diameter
•
Measure the oversized piston diameter
by means of a micrometer.
N.B.
- THE MEASUREMENT MUST BE CARRIED OUT IN COR-
RESPONDENCE WITH THE INDICATED POINT H = 15 MM.
- CARRY OUT THE MEASUREMENT IN AN ORTHOGONAL
POSITION WITH RESPECT TO THE PIN
.
•
Calculate the cylinder finishing size, as follows:
A : Piston diameter
B : Cylinder piston clearance 0.025 - 0.045 mm
C : Grinding tolerance 0.02 mm
D : Finishing diameter
D = A + B - C
PORTER 1.3 16V
Engine
EN - 311