The Howard Bantam had several different engines over the years. Early models had a Villiers Mk25c, later a Howard AC engine was fitted. Other engines included BSA, Villiers 4 stroke B&S etc.
A photograph of the engine on your machine will help identify it. A 2 stroke can usually be identified by the lack of any means of adding oil to the sump (crankcase) as petrol 2 strokes rely on the oil in the fuel mixture for lubrication.

A photograph of the engine will help confirm make and model and ensure correct information is supplied.