The B100 mounts a high-performance 118 cm³ 2-stroke air-cooled 1-cylinder engine on an astonishingly robust and lightweight 88 kg chassis using a pressed steel sheet frame. B100 was chosen as the name of this model despite an engine displacement of 118 cm³. The engine generates maximum torque of 10.8 N·m at only 4,000 rpm, making it particularly easy to ride. An aluminum cylinder was adopted for greater durability. This model is also extremely fuel efficient and could, on paper, be ridden between Tokyo and Osaka on a single full tank of gas. It combines the dynamism of a 125 cm³ class bike with a large chassis to realize stable riding performance. In 1966, two years after its debut, the model was renamed the B120.

Dimensions and weight	Dimensions	Overall length	1,905 mm
		Overall width	665 mm
		Overall height	965 mm
	Wheelbase		1,220 mm
	Weight		88 kg
Engine	Engine type		2-stroke, 1-cylinder, air-cooled
	Engine displacement		118 cm³
	Bore x stroke		52.0 mm × 56.0 mm
	Maximum power		6.6kW(9PS) / 7,000rpm
	Maximum torque		9.6N-m / 4,000rpm
Transmission			4-speed constant mesh
Front tire size			2.50-17-4PR
Rear tire size			2.75-17-4PR