VS5 Vespa GS 150
Frame VS51T · 1958–1961 · Large frame
Engine
TypeSingle cylinder, air cooled 2-stroke
Barrel2 transfer ports
InductionPiston ported
Bore × stroke57 mm × 57 mm
Displacement145.6 cc
Compression ratio7.1 : 1
Power8 bhp @ 7,000 rpm
Lubrication6% premix
Transmission
Type4 speed constant mesh
Primary drive22/67
1st gear14.72 : 1
2nd gear10.28 : 1
3rd gear7.61 : 1
4th gear5.84 : 1
ClutchWet, multiplate
Carburetor
CarburetorDell'Orto UB 23 S3 I
Main jet103
Slow-running jet50
Needle position3
Mixer2.60
Ignition & Electrical
IgnitionContact breaker & coil
Timing27° BTDC
Breaker gap0.4 mm
Stator output6v - 35w
System6 volt
Wheels & Tires
Wheels10″
Wheel hubsCast w/cooling fins
Tires3.50 × 10
Tire pressure (front)16 psi
Tire pressure (rear, solo)20 psi
Tire pressure (rear, 2-up)32 psi
Performance
Top speed63 mph