The B-1 was the first model garden tractor that was sold by Allis Chalmers in 1961. It was built by Simplicity and is very close to the Simplicity model 725. It has a Briggs 7 1/4 horse power motor and a 3 speed forward tranny. It came with an early style bolt together mower deck, mulcher kit for the deck, and an optional low speed pulley kit. The engine was rebuilt sometime in it's life and runs very well.