Inspecting the crankshaft plain bearings
- T
o obtain a good bushing lubrication it is necessary
to have both an optimal lubricating pressure (3,2
bar) and a good oil flow rate; the bushings must be
correctly positioned so as not to obstruct the oil
supply channels.
- The main bushings are comprised of two half-
bearings, one with holes and channels for lubrica-
tion whereas the other is solid.
- The solid half-bearing is intended to stand the
thrusts caused by combustion, and for this reason
it is arranged opposite the cylinder.
- To prevent obstructions in the oil feeding chan-
nels, the matching surface of the two half-bearings
must be perfectly perpendicular to the cylinder ax-
is, as shown in the figure.
- The oil feeding channel section is also affected
by the bushings driving depth compared with the
crankshaft axial clearance of the limiting surface.
- Check the inside diameter of the main bushings
in the three directions indicated in the diagram.
- Repeat the measurements for the other bushing
half. see diagram.
- There are three crankcase versions: with RED
main bushings, with BLUE main bushings and with
YELLOW main bushings.
- There is only one type of main bushing housing
hole in the crankcase
The standard bushing diameter after driving is var-
iable on the basis of a coupling selection.
- The bushing housings in the crankcase are avail-
able in two categories, Cat. 1 and Cat. 2, as are
the crankshafts.
- The main bushings are available in three thick-
ness categories, identified by colour markings, as
shown in the table below.
Vespa GTV 125
Engine
ENG - 55
Summary of Contents for GTV 125
Page 4: ......
Page 6: ......
Page 7: ...INDEX OF TOPICS CHARACTERISTICS CHAR ...
Page 20: ...Characteristics Vespa GTV 125 CHAR 14 ...
Page 21: ...INDEX OF TOPICS TOOLING TOOL ...
Page 34: ...Tooling Vespa GTV 125 TOOL 14 ...
Page 35: ...INDEX OF TOPICS MAINTENANCE MAIN ...
Page 57: ...INDEX OF TOPICS TROUBLESHOOTING TROUBL ...
Page 64: ...Troubleshooting Vespa GTV 125 TROUBL 8 ...
Page 65: ...INDEX OF TOPICS ELECTRICAL SYSTEM ELE SYS ...
Page 89: ... Refit the battery cover Vespa GTV 125 Electrical system ELE SYS 25 ...
Page 90: ...Electrical system Vespa GTV 125 ELE SYS 26 ...
Page 91: ...INDEX OF TOPICS ENGINE FROM VEHICLE ENG VE ...
Page 98: ...Engine from vehicle Vespa GTV 125 ENG VE 8 ...
Page 99: ...INDEX OF TOPICS ENGINE ENG ...
Page 156: ...Engine Vespa GTV 125 ENG 58 ...
Page 167: ... Remove the maximum nozzle Remove diffuser Vespa GTV 125 Engine ENG 69 ...
Page 177: ...INDEX OF TOPICS SUSPENSIONS SUSP ...
Page 199: ...INDEX OF TOPICS BRAKING SYSTEM BRAK SYS ...
Page 215: ...INDEX OF TOPICS COOLING SYSTEM COOL SYS ...
Page 221: ...INDEX OF TOPICS CHASSIS CHAS ...
Page 237: ...INDEX OF TOPICS PRE DELIVERY PRE DE ...
Page 241: ...INDEX OF TOPICS TIME TIME ...