APRILIA Atlantic 300 Service Station Manual page 31

ATLANTIC 300 i.e.
Slot packing system
Characteristic
Compression ratio
10.5 ÷ 11.5 : 1
Distance "A" to be measured is a value of piston recess, it indicates by how much the piston crown
descends below the plane formed by the cylinder crown. The further the piston enters into the cylinder,
the thinner the base gasket to be used should be (to compensate the compression ratio) and vice versa.
NOTE
DISTANCE «A» SHOULD BE MEASURED WITH NO GASKET FITTED BETWEEN THE CRANK-
CASE AND THE CYLINDER AND AFTER RESETTING THE DIAL GAUGE, WITH SUPPORT, ON A
GROUND PLANE
Characteristics
CHAR - 31