cylinder head and the oil drainage duct at the fly-
wheel side oil seal.
- Inspect the coupling surfaces on the crankcase
halves for scratches or deformation, taking partic-
ular care with the cylinder/crankcase surfaces and
the crankcase halves surfaces.
- Defects in the crankcase coupling gasket be-
tween the crankcase halves or the mating surfaces
shown in the diagram, could cause a drop in the
oil pressure lubricating the main bearings and con-
nection rod.
- Check the main bearing seats that limit axial
clearance in the crankshaft show no signs of wear.
The dimension between these seats is measured
by way of the procedure described previously for
measuring the crankshaft axial clearance and di-
mensions.
N.B.
THE JET IS FED THROUGH THE MAIN BUSH-
INGS. PROPER OPERATION OF THIS COMPO-
NENT IMPROVES THE PISTON TOP COOLING.
CLOGGING HAS EFFECTS THAT ARE DIFFI-
CULT TO DETECT (PISTON TEMPERATURE
INCREASE). FAILURE OR LEAK CAN CONSID-
ERABLY DECREASE THE MAIN BUSHING
AND CONNECTING ROD LUBRICATION PRES-
SURE.
N.B.
THE HEAD LUBRICATION CHANNEL IS PRO-
VIDED WITH A SHUTTER JET; THIS GIVES A
"LOW PRESSURE" HEAD LUBRICATION; THIS
CHOICE WAS MADE TO REDUCE THE OIL
TEMPERATURE IN THE SUMP. THE JET
CLOGGING IMPAIRS THE HEAD LUBRICA-
TION AND THE TIMING MECHANISMS. A JET
FAILURE CAUSES A DECREASE OF THE MAIN
BUSHING AND CONNECTING ROD LUBRICA-
TION PRESSURE.
Engine
Vespa GTV 125
ENG - 54
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 ...