Introduced in 1954 using the same basic plunger frame and engine as the D1. The engine being bored out to 150cc and heavier weight forks fitted. This model used the same BD2s frame number sequence as the D1 which ran in parallel.
1956 saw the introduction of the first swinging arm D3 model the plunger frame being dropped for this model but remaining for the D1. The bike was at this time given a D3 frame number designation.