PIAGGIO MSS ZIP 100 4T Service Manual page 94

Engine
Specification
Measure detected
Base gasket thickness
Specification
Cylinder height
Head gasket thickness (steel)
Measure detected
Base gasket thickness
Measure detected
Base gasket thickness
This engine is manufactured with two different head gasket solutions:
- Fibre gasket drw. 969244 0.95 mm thick.
- Steel gasket drw. 969393 0.3 mm thick.
In order to guarantee an adequate compression ratio, the gaskets match cylinders with different heights:
- Fibre gaskets with cylinder 56.45 mm high
- Fibre gaskets with cylinder 57.15 mm high
In order to carry out the revision both gaskets should be present on the spare parts.
All pin-piston-cylinder units supplied with the spare parts present cylinders 57.15 mm high
N.B.
MEASUREMENT "A" TO BE TAKEN IS A VALUE OF PISTON RE-ENTRY, IT INDICATES BY HOW
MUCH THE PLANE FORMED BY THE PISTON CROWN FALLS BELOW THE PLANE FORMED BY
THE TOP OF THE CYLINDER. THE FURTHER THE PISTON GETS INSIDE THE CYLINDER, THE
THINNER THE HEAD GASKET TO BE APPLIED SHOULD BE (TO RECOVER THE COMPRESSION
RATIO) AND VICE VERSA.
Characteristic
Shimming system to control the compression ratio
CR: 11.1 ÷ 12.9
Name
shimming_1
shimming_2
ENG - 94
CYLINDER BASE GASKET THICKNESS
PISTON PROTRUSION CHECK
Measure A
0.05 ÷ 0.25
0.25 ÷ 0.40
MSS ZIP 100 4T
Desc./Quantity
1 ± 0.05
0.5
Desc./Quantity
57.15 ± 0.05
0.3 ± 0.05
0.20 ± 0.05
0.4
0.30 ± 0.05
0.5
Thickness
0.35
0.25