PIONEER 620:
YEAR INTRODUCED: 1960
YEAR DISCONTINUED: 1962
ENGINE DISPLACEMENT: 6.21 cu. in. (103cc)
NUMBER OF CYLINDERS: 1
CYLINDER BORE: 2.25 in.(57mm)
PISTON STROKE: 1.5625 in. (40mm)
CYLINDER TYPE: Aluminum with cast iron liner
INTAKE METHOD: Piston ported
Improved version of model 610