The 'Pre-WD' type was introduced around 1923 as an attempt to cater for the small power market. The single flywheel model was rated at 1.5 HP, the twin flywheel model was rated at 2 HP. Not many of these engines have survived into preservation, this is probably due to sales volumes being relatively low at this stage. It is likely that other manufacturers such as Petter had cornered the small power market with the small two-stroke M type engines. The Pre-WD type introduced the familiar hopper style that continued throughout the later production runs of WD type engines. The 1.5 and 2 HP engines differ significantly in constrution, the crankcase and method of driving the magneto being the main difference. Production of the 'Pre-WD' type ceased in 1937.