Patent attributes
A rotary throttle valve carburetor has a start assist device with an operating member that interacts with a throttle lever of the throttle valve to axially displace the throttle valve, preferably without rotating it. The operating member may be rotated and moved linearly for selective engagement with the throttle lever by any one of a plurality of starting features generally spaced circumferentially about the operating member. Preferably, each starting feature has a face that faces axially outward with respect to the rotary axis and when in contact with the throttle lever. Each face is spaced at a different distance from the operating member axis thus selection of each will cause the operating member to contact and move the throttle lever a different distance. The different distances correspond to varying fuel enrichments that may be associated with different temperatures of an engine to be started.