720 Serial numbers

Simplicity tractors continued to be built in Port Washington, but for the first time there were differences besides paint and decals. In 1971, the 300 series introduced many design changes. The body was painted orange and the hoods painted cream, and Kohler engines were used for the first time. In 1973 the similar 400 series was introduced. These tractors bore little resemblance to the Port Washington built Simplicity models. The mower decks and many of the attachments were different. Also in 1971, the B-207 and B-208 were updated to the new paint scheme, but retained Briggs power. The 206, 207, and 208 were continued as the Homesteader series from 1972 to 1974. Also in 1972, Allis-Chalmers introduced the model 616, which was the Simplicity PowrMax with orange paint and a different hood. The 616 became the 620 in 1973 with the new 20 horsepower engine. In 1975 the 620 was relabeled as the 720 to match the numbering of the updated smaller tractors. To the best of our knowledge the 620 and 720 models are identical except that the later 720’s had an upgraded front axle. AC later came out with a second model 616, which was a painted over Simplicity 4216 and had no relation to the earlier “PowrMax” 616.

During the Nixon administration, most of the fair trade laws were repealed, so in 1973 Allis-Chalmers closed the Lexington plant and transferred all production back to Port Washington. Once again, AC and Simplicity Garden tractors became identical except for paint and decals, although certain individual models may or may not have had an exact Simplicity counterpart.

In 1974, the new 700 series was introduced in an all orange color scheme to match the big AC farm tractors. This series used Kohler engines but there were some Briggs powered 716’s. The new 600 series introduced at the same time replaced the Homesteader line and the 800 series lawn tractors were added in 1976. The 600 and 800 series tractors used Briggs engines exclusively. The 900 series replaced the 700 series in 1979 using only Kohler engines, however a very few Briggs powered 916’s were made.

http://simpletractors.com/Main/history.htm

http://www.simpletractors.com/Main/made_when.htm

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