S p e c s:

1953 - 1954
Made under license in France
engine: single cylinder, air cooled 2-stroke
induction: piston ported
bore: 54 mm
stroke: 54 mm
cubic capacity: 123.67 cc
compression ratio: 6.4: 1
bhp at rpm: 5 @ 4,850
lubrication: 5% oil
transmission: 3 speed constant mesh
primary drive: 22/67
1st gear: 12.2: 1
2nd gear: 7.6: 1
3rd gear: 4.85: 1
clutch: wet - 3 cork plates
carburetor: Guertner R.N.V.18
venturi diameter: 22mm
barrel manifold: 18mm
main jet: 32
idle jet: 32X2
throttle slide: No. 11
 
OR
carburetor: Dell'Orto TA/18
venturi diameter: 22mm
barrel manifold: 18mm
main jet: 80/100
idle jet: 35/100
throttle slide: No. 70
ignition: contact breaker & coil
ignition timing: 28 degrees BTDC
breaker gap: 0.3 - 0.5 mm
voltage: 6 volt AC
battery: n/a
wheels: 8"
tires: 3.50 x 8"
top speed: 47 mph / 75 kph
 
 
Note: ACMA produced Vespas from 1951 to 1962 in Fourchambault, near Dijon, France. Some interesting features of the 1953-54 model were:
  • The fan cover is visible through a cut out in the motor side cowl on the '53 but has louvers on the '54.
  • A special exhaust w/two pipes
  • Available in light metallic green in '53
  • Available in light green in '54
  • 8" wheels
  • A trapezoidal rear light
  • The cast headlamp was bolted to the handlebars and included a speedometer
  • X style rear rack

Although they look very similar, there are some small differences between the 1953-54 ACMA 125 and the earlier model which are listed on the ACMA 125 1951-52 page.

The engine is very similar to the 1952-53 Italian Vespa 125 and many parts should be interchangeable.

Thanks to Jean-François Bourque for the info and pictures (click images below for larger images).