Had some of those in the shop back early 2000's from Walmart. Never had to work on that side of it but did other repairs on the mowers.
Briggs has had other ideas that just never seemed to really take off. the rider engine with stator that produced 1500 watts for a powered 120v AC outlet on the mower. The mowers with the removable rechargable battery for the electric start.
Or the 15 hp electric motor designed for golf carts and was actually used on their electric outboard boat motors that didn't have any connectors to hold the two halves of the motor together. the neodymium rare earth magnets had enough pull to hold it together.