Carburettor needle valve adjustment limiter cap and method of adjusting fuel flow.

摘要

A cap (40) and method for limiting the range of adjustment of a fuel flow metering valve (36) in a carburetor. The cap (40) has a body (82) with an arm (84) projecting generally radially outwardly therefrom to abut against a stop carried by the carburetor to limit valve rotation and a passage (86) therein for telescopically axially receiving the head end (62) of a shank (60) of the valve (36). Portions within the passage (86) enable the cap (40) to be retained on the shank (60) of the valve (36) in a freely rotating first position during assembly and arm orientation, in a second position securing the cap (40) to the valve (36) to limit adjustment and maintain emissions calibration, and in a third position to releasably drivingly engage the valve (36) to perform fuel flow adjustment before securing the cap (40) to the valve (36).