Villiers 31A

The 31A was introduced 1958 as a 250 version of 9E Bore x stroke = 66 x 72 = 249 CR 7.4:1 4 speed wide ratio gearbox carb S25/1 31A was developed to power the Bond minicar and as road engine but quickly found a niche as a trials engine Mk 31AS 31A4 31ASR were fitted with starter, or starter + reverse