Introduced in 1987, the Série 7 was decidedly more car-like in appearance than the earlier JS4-derived Série 5. The increase in length also made the car more practical, with a considerably larger cargo area. The car was introduced with a 325 cc single-cylinder diesel engine, but this was soon replaced with an air-cooled 265 cc engine built by Fuji Robin in Japan. Power for the original engine was 5 hp (3.7 kW) and top speed was no more than 45 km/h (28 mph) in order to stay within the parameters for sans-permis vehicles. The later engine develops a claimed 4 kW (5.4 hp), reflecting adjustments in French law resulting from the adoption of SI units.
There was also a version called the Série 7 Twin (or 650 Twin) which required a special quadricycle license and was taxed at 1CV (one tax horsepower, the lowest rating possible). This had a two-cylinder diesel engine built by Italy's Ruggerini Motori [fr]. To meet local requirements, German importer AutoTechnik Walther (ATW) offered a 49-cc version with a Sachs two-stroke engine with 3 kW (4 hp). This was sold as the Ligier ATW 50L (later the ATW-Plus 50L).