Wisconsin Air Cooled TRA-10D Instruction Book And Parts List page 43

located in the air entrance and operated externally by a lever
mounted on the shaft. The choke valve is used to restrict the air
entering the carburetor. This increases the suction on the jets
when starting the engine. The choke valve is of a "semi-auto-
matic" type, having a poppet valve incorporated in the design,
which is controlled by a spring. The poppet valve opens automati-
cally when the engine starts and admits air to avoid over-choking
Parts are identified by reference number. See parts list for correct part number.
or flooding of the engine. The mixture required for starting is
considerably richer than that needed to develop power at normal
temperatures. As the engine fires and speed and suction are in-
creased, the mixture ratio must be rapidly reduced. This change is
accomplished through adjustment of the choke valve and the
automatic opening of the poppet valve to admit more air when the
engine fires.
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