Inspecting the valves
- Measure the width of the sealing surface on the
valve seats and on the valves.
Sealing surface width: After use: Intake and ex-
haust: 1.6 mm
- If any of the sealing surfaces on the valves is
wider than the specified limit or is damaged in one
or more points, or curved, replace the valve with a
new one.
CAUTION
DO NOT REVERSE THE FITTING POSITIONS
OF THE VALVES (RIGHT - LEFT).
Characteristic
Valve wear check Standard: Intake and ex-
haust:
0.99 - 1.27 mm
- Measure the diameter of the valve stems in the three positions indicated in the diagram.
- Calculate the clearance between valve and valve guide.
- Check that there are no signs of wear on the surface of contact with the articulated register terminal.
- If the checks above give no failures, you can use the same valves. For best sealing results, it is
advisable to grind the valves. Grind the valves gently with a fine-grained lapping compound. During the
grinding, keep the cylinder head with the valve axes in a horizontal position. This will prevent the lapping
compound residues from penetrating between the valve stem and the guide (see figure).
CAUTION
TO AVOID SCORING THE CONTACT SURFACE, DO NOT KEEP ROTATING THE VALVE WHEN
NO LAPPING COMPOUND IS LEFT. CAREFULLY WASH THE CYLINDER HEAD AND THE
VALVES WITH A SUITABLE PRODUCT FOR THE TYPE OF LAPPING COMPOUND BEING USED.
N.B.
DO NOT CHANGE THE POSITIONS THE VALVES ARE FITTED IN
Characteristic
Valve check standard length
Outlet: 94.4 mm
Valve check standard length
Inlet: 94.6 mm
Valve check Maximum admissible clearance
Outlet: 0.072 mm
Valve check Maximum admissible clearance
Inlet: 0.062 mm
Valve check standard clearance
Outlet: 0.025 ÷ 0.052 mm
Vespa GTS 250 I.E.
Engine
ENG - 41
Summary of Contents for GTS 250 I.E.
Page 1: ...WORKSHOP MANUAL 633577 Vespa GTS 250 I E ...
Page 4: ......
Page 6: ......
Page 7: ...INDEX OF TOPICS CHARACTERISTICS CHAR ...
Page 19: ...INDEX OF TOPICS TOOLING TOOL ...
Page 32: ...Tooling Vespa GTS 250 I E TOOL 14 ...
Page 33: ...INDEX OF TOPICS MAINTENANCE MAIN ...
Page 47: ...INDEX OF TOPICS TROUBLESHOOTING TROUBL ...
Page 51: ...INDEX OF TOPICS ELECTRICAL SYSTEM ELE SYS ...
Page 56: ...Front side 1 Saddle opening switch 2 Wirings Electrical system Vespa GTS 250 I E ELE SYS 6 ...
Page 90: ... Refit the battery cover Connectors Electrical system Vespa GTS 250 I E ELE SYS 40 ...
Page 91: ...INDEX OF TOPICS ENGINE FROM VEHICLE ENG VE ...
Page 98: ...Engine from vehicle Vespa GTS 250 I E ENG VE 8 ...
Page 99: ...INDEX OF TOPICS ENGINE ENG ...
Page 156: ...Engine Vespa GTS 250 I E ENG 58 ...
Page 164: ...Engine Vespa GTS 250 I E ENG 66 ...
Page 165: ...INDEX OF TOPICS INJECTION INJEC ...
Page 168: ...Injection Vespa GTS 250 I E INJEC 4 ...
Page 184: ... REMOTE CONTROLS CONTROL UNIT FUSES ETC Injection Vespa GTS 250 I E INJEC 20 ...
Page 198: ...Components location Injection Vespa GTS 250 I E INJEC 34 ...
Page 204: ...Injection Vespa GTS 250 I E INJEC 40 ...
Page 218: ...Injection Vespa GTS 250 I E INJEC 54 ...
Page 219: ...INDEX OF TOPICS SUSPENSIONS SUSP ...
Page 240: ...Suspensions Vespa GTS 250 I E SUSP 22 ...
Page 241: ...INDEX OF TOPICS BRAKING SYSTEM BRAK SYS ...
Page 257: ...INDEX OF TOPICS COOLING SYSTEM COOL SYS ...
Page 260: ...Cooling system Vespa GTS 250 I E COOL SYS 4 ...
Page 261: ...INDEX OF TOPICS CHASSIS CHAS ...
Page 273: ...INDEX OF TOPICS PRE DELIVERY PRE DE ...
Page 277: ...INDEX OF TOPICS TIME TIME ...