Model F series 1916-1922
The early production model F's featured a Linga Vaporizer carburetor. This carb was a rather complicated affair with 3 separate chambers built into a large single brass bowl, one for gas, one for kerosene and the other for water. This arrangement meant that you had 3 separate floats to contend with also. Later in the F production the switch was made to a Wheeler-Schebeler carb of a simplier design.

The home built governor that came out on early F's was replaced later in production by a belt driven Pickering governor that stayed with the rest of the Eagle tractors until the end of production of the 2 cylinder models in 1930.

Another noticeable consmetic change in the F's was the change from a cast iron water tank mounted on top of the engine block (many people not familiar with Eagle 2 cylinder tractors think this is a water cooling tank for the engine, but what it really is, is the water storage tank for the engine water feed valve) to a sheet metal tank. This model also had the change from the domed top radiator tank to the squared off style.

Model H series 1922-1930
The 20-40 had several cosmetic differences, they came in three variations, Regular, Improved, and Special chassis. The later two had wider rear wheels and heavier bull gears and pinions, this was better suited to pulling heavy threshing machines around and for field work. The 22-45 also had three chassis versions as the 20-40, but it is not known if they differentiated them within the model number. A number of 20-40 Improved and Specials were upgraded to 22-45 by replacement of the engine block to the larger size.