Gilera 633721, Workshop Manual

Page: 16 / 407

AXIAL CLEARANCE BETWEEN CRANKSHAFT AND CONNECTING ROD
Name Description Dimensions Initials Quantity
Transmission-side
shoulder
0.8 ± 0.025 A D= 0.20 - 0.40
Transmission-side half-
shaft
19.6 + 0.050 B D= 0.20 - 0.40
Connecting rod 22 0.10-0.15 C D= 0.20 - 0.40
Flywheel-side shoulder 13 ± 0.025 F D= 0.20 - 0.40
Flywheel-side half-shaft 19.6 +0.050 E D= 0.20 - 0.40
Complete drive shaft 63.5+0.1-0.05 G D= 0.20 - 0.40
Characteristic
Drive shaft / crankcase axial clearance:
0.1 - 0.5 mm (when cold)
Slot packing system
Shimming system for limiting the compression ra-
tio Rc = 10.5 : 1
DISTANCE «A» IS A PROTRUSION OR RE-
CESS VALUE OF THE PISTON CROWN WITH
RESPECT TO THE CYLINDER PLANE.
DISTANCE «A» HELPS DETERMINE THE
THICKNESS OF GASKET «B» THAT HAS TO
BE FITTED TO THE CYLINDER HEAD IN OR-
DER TO RESTORE COMPRESSION RATIO.
BASE GASKET «B» MUST BE THICKER THE
MORE THE PLANE FORMED BY THE PISTON
TOP PROTRUDES FROM THE PLANE
FORMED BY THE CYLINDER HEAD. ON THE
OTHER HAND, THE MORE THE PISTON TOP IS
RECESSED INTO THE CYLINDER TOP PLANE,
THE SMALLER THE GASKET THICKNESS.
BASE GASKET THICKNESS
Name Measure A Thickness
«A» MEASURE TAKEN - 0.185 - - 0.10 0.4 ± 0.05
«A» MEASURE TAKEN - 0.10 - + 0.10 0.6 ± 0.05
«A» MEASURE TAKEN + 0.10 ÷ + 0.185 0.8 ± 0.05
N.B.
VALUES INDICATED WITH «-» REFER TO PISTON CROWN RECESSES WITH RESPECT TO THE
CYLINDER PLANE.
Characteristics
Nexus 500 euro 3
CHAR - 16