Walbro Corporation

Karl P Richter

George M Pattullo

Eric L King

Jerry J Ashcraft

Jose Govea

Randy M Sherman

A diaphragm type carburetor which has a purge system to remove air and fuel vapor from the carburetor and to fill it with liquid fuel prior to starting an engine fed by the carburetor. The purge system has a primer valve actuated by moving a choke valve of the carburetor to its closed position to inject a small volume of liquid fuel into a throttle bore to provide a richer fuel and air mixture to the engine to facilitate starting it. Desirably, the small volume of liquid fuel is injected into the throttle bore in response to closing of the choke valve without requiring any additional steps such as depressing a button on the carburetor, to do so. Preferably, the choke valve is carried on a shaft which has at least one detent formed therein to provide a camming surface which actuates the primer valve as the choke valve is rotated from its open position to its closed position. Preferably, the choke valve shaft has a pair of detents. The primer valve is partially received by one detent when the choke valve is fully opened to close the primer valve and prevent any fluid flow therethrough. A second detent partially receives the primer valve to also close the primer valve after the choke valve has been moved to its fully closed position. The camming surface is disposed between the two detents relative to the movement of the choke valve to temporarily open the primer valve and inject the desired quantity of liquid fuel into the throttle bore to assist starting the engine when the choke valve is moved between its open and closed positions.

Carburetor with purge prime system

A needle valve limiter cap of single-stage and two stage types having a hollow cylindrical outer body of rigid material, carrying a limiter arm. A spring steel hollow retainer clip sleeve is telescopically received in the body and has inwardly and outwardly protruding resilient barbs reversely oriented relative to one another to respectively engage the cap body and the needle valve shank to respectively prevent retrograde relative telescopic motion between the clip and the body and between the clip and valve shank. Easy seating of the single or two-stage caps into their locked first and/or second stage needle adjustment positions also produces an audible click and feel as the inwardly protruding spring barb(s) snap into a needle shank groove or grooves. A cap living-hinge type anti-tamper flap at the cap end prevents access of any adjustment tool to a needle valve head. A 'peanut clip' cap orientor and holder encircles the cap bodies to hold them in a paired side-by-side subassembly for storage, shipment and/or telescopic installation and rotational orientation of the caps simultaneously on their respective needle valve shanks. A peanut clip stop leg automatically halts initial push-on assembly of the paired cap bodies and peanut clip at first stage position. Cap limiter arm entrapment extensions on the holder clip lock the caps angularly in rich-rich orientation only in first stage position. Improved forms of needle valves with shank grooves, cooperating barb retaining shoulders, an anti-pry-off cap abutment conical shoulder and anti-tamper adjustment head cooperate with the limiter caps.

Carburetor needle valve adjustment limiter cap apparatus and method of

A tool for removing a carburetor needle valve adjustment limiter cap has a handle with a set of jaws at one end for engaging the end cap and an actuator at the opposite end for applying force to the jaws to remove the end cap from the valve body. In a preferred form, the actuator has a slidable weight or mass that can be reciprocated along the handle to impact against a stop on the handle at an end opposite from the jaws. In another form, the actuator has a rod extending transversely through the handle and secured to it. In use, the rod is positioned against an abutment to provide a fulcrum about which the handle is pivoted to produce a force to pull the end cap from the valve body.

Growing community of inventors

Sahuarita, AZ, United States of America

Karl P Richter