Piaggio Vespa PX 125 & PX 150 Euro 2 Service Manual

Piaggio introduced the large-frame PX lineage at the end of the 1970s, building on the long-running Vespa formula of a pressed-steel monocoque body, compact two-stroke engine and handlebar-operated manual transmission. Vespa’s official historical timeline identifies the P125X, presented at the 1977 Milan Show and launched as the new PX 125, as a major step in the family, with more angular bodywork, a redesigned handlebar and an updated front suspension. That basic architecture remained recognizable for decades and became one of the most enduring forms in Vespa history. See the official Vespa historical timeline for the original PX context.

The PX125 Euro 2 in this factory publication uses a 123.4 cm³ air-cooled two-stroke single with a 52.2 × 57 mm bore and stroke and an 8:1 compression ratio. Fuel is supplied by a Dell'Orto SI 20/20 D carburetor, while lubrication is handled by a separate oil tank and automatic mixer rather than requiring the rider to premix every tank. Factory output is listed at 6 kW (8 hp) at 5,600 rpm. Starting is by both electric starter and kick-start, and the four-speed gearbox retains the traditional Vespa hand-shift layout.

The PX150 Euro 2 follows the same mechanical concept with a 150.599 cm³ engine using a 58 × 57 mm bore and stroke, the same 8:1 compression ratio and Dell'Orto SI 20/20 D carburetor. Factory output is 6.6 kW (9 hp) at 5,700 rpm. Both versions use forced-air cooling from a centrifugal fan, electronic capacitive-discharge ignition, a 12 V electrical system and the characteristic engine-and-transmission assembly mounted beside the rear wheel.

Chassis design remains deliberately traditional. The PX uses a pressed-steel monocoque frame, 10-inch interchangeable wheels, a single-sided front suspension arrangement with coil spring and hydraulic damping, and a rear engine-mounted suspension unit. The Euro 2 specification combines that classic layout with a 220 mm hydraulically operated front disc brake and a 140 mm mechanically operated rear drum. Together with the four-speed transmission and two-stroke engine, these features make it a classic manual-shift two-stroke Vespa scooter rather than a modern automatic CVT scooter.