The 5 HP Abenaque boasts many unique features.
The Abenaque engine first appeared around 1895, and received patent protection with patent number 612,756 issued in 1898. Subsequent patents were issued in 1900, 1902 and 1903.
Abenaques contain several unique features. Ignition is provided by a “star-wheel” igniter. The igniter utilizes a small insulated wire that “rubs” a wheel resembling a star. When the point of the star rubs off the wire, a hefty spark is produced. This method also constantly cleans the ignition system, preventing issues due to carbon buildup.
Another unique feature is the fuel injector, which is adjustable to allow enrichment or leaning of the fuel. The fuel pump makes only one stroke during the compression cycle and then remains idle until another power stroke is needed.
Early Abenaque engines also have a “dog bone” governor, so named because of its resemblance to one. Even with its odd appearance the governor works surprisingly well, keeping the engine at a fairly constant speed for a hit-and-miss model.
The Abenaque also has an enclosure over the connecting rod and crankshaft. No oiler is used on the cylinder bore and a splash system lubricated all internal moving parts. In this regard, Abenaque was considerably ahead of its time.
Perhaps the most unique feature of Abenaque engines is its cooling system. Large thin tanks are used to provide a maximum surface area to enhance cooling. Many of the tank-cooled Abenaques were converted to hopper-cooled models if they were ever returned to the factory for service.