Walbro Corporation

Walbro Engine Management, L.l.c.

Eric L King

George M Pattullo

John C Woody

Kevin L Israelson

Matthew A Braun

Albert L Sayers

Terry O Hendrick

Timothy K Grifka

David L Speirs

Mark S Swanson

Cyrus M Healy

Kenneth J Cotton

Roger N Smith

David D Hacker

Karl P Richter

In at least some implementations, a locking plate may be received between the cover plate and the adjustable valve and be movable to a first position permitting access to the adjustable valve and a second position inhibiting or preventing access to the adjustable valve. In some implementations, a latch assembly may releasably retain the locking plate in its second position. The latch assembly may include a finger carried by the locking plate and releasably engageable with a stop when the locking plate is in its second position.

Charge forming device with tamper resistant adjustable valve

In at least some implementations, a coupler for a spark plug includes a body formed from an electrically conductive material and including a first connecting portion defining a first cavity, and a second connecting portion defining a second cavity spaced from the first cavity, and the body includes an intermediate portion physically and electrically coupling the first connection portion and the second connecting portion. In at least some implementations, the first connecting portion is formed from a wire coiled to define the first cavity within the coil. In at least some implementations, the second connecting portion is formed from a wire coiled to define the second cavity within the coil.

Spark plug coupler

A carburetor with a body with a cavity in which an adjustable fuel valve is received. To inhibit access to and manual adjustment of the valve, a cover may overlay at least a portion of the adjustable valve. In some forms, a releasable lock plate may be received between the cover and the adjustable valve. Specialty tools may release the lock plate and adjust the valve.

In at least some implementations, a valve for a charge forming device, includes a needle having a first end and a second end, and a valve body. The valve body has an axis extending between a first end and a second end, and a cavity open to the second end and in which part of the needle is received with the second end of the needle extending out of the second end of the valve body. The valve body also has a projection extending axially from the first end of the valve body to a free end of the projection, and the valve body has at least one drive surface axially spaced from the free end, the drive surface extends axially and radially.

Tamper resistant adjustment valve for a charge forming device

A carburetor with a fuel and air mixing passage and a fuel delivery system may include a valve actuated by a diaphragm with no penetrations through at least the portion of the diaphragm exposed to a fuel metering chamber. The diaphragm may include at least two convolutions increasing a surface area of the portion of the diaphragm exposed to the fuel metering chamber relative to the surface area of a plane exposed to and covering the fuel metering chamber. A diaphragm may be in the form of a bellows with at least two convolutions. The diaphragm may be made of a suitable polymer or one or more pieces of a thin metal sheet or foil.

Carburetor with fuel metering diaphragm

A starting system for a combustion engine including a carburetor with a throttle valve moveable between idle and wide open positions, a throttle control to control movement of the throttle valve during normal operation of the engine, and a linkage between the throttle control and the throttle valve. The starting system includes a recoil pulley, a pull-cord to rotate the recoil pulley, an actuator moveable in response to rotation of the recoil pulley, and a throttle override device. The throttle override device has a first control member moveable from a first position to a second position in response to movement of the actuator, and a second control member moveable in response to movement of the first control member from a first to a second position. The second control member is operably associated with the linkage to prevent the throttle valve from being in its wide open position when the second control member is in its second position.

Engine starting system with throttle override

A fuel vapor separator includes a polymeric body that preferably has a polymeric canister and a polymeric lid secured to the canister to define a liquid tight enclosure. The enclosure is preferably divided into at least two chambers. One chamber preferably receives liquid fuel and communicates with a heat exchanger to cool the supply of liquid fuel therein. Vapor is trapped in a vapor dome area above the liquid fuel and is vented through a vent valve carried by the fuel vapor separator. The other chamber of the enclosure preferably receives a high pressure fuel pump adapted to receive liquid fuel from the first chamber, and to deliver liquid fuel under pressure to the engine. Preferably, the chamber in which the fuel pump is received is communicated with a coolant to facilitate cooling the fuel pump in use.

Fuel vapor separator

A fuel shut-off system for a carburetor substantially reduces or prevents the delivery of fuel to an engine when the engine is turned off and as it coasts to a stop. The fuel shut-off system preferably reduces or eliminates the pressure differential across a nozzle through which fuel is delivered from a fuel chamber through a fuel-and-air mixing passage of the carburetor and into the engine. In this manner, the flow of fuel through the nozzle is reduced and preferably eliminated immediately upon engine turn-off to prevent the after-fire and associated problems within a residually hot exhaust system. The system incorporates an actuator, preferably a solenoid valve, having a first position which obstructs a vacuum bypass passage communicating between the fuel chamber and the fuel-and-air mixing passage, and a second position which enables communication between the vacuum bypass passage and a fuel chamber passage which otherwise communicates with a near atmospheric pressure source.

Carburetor fuel shut-off system

A carburetor has an upper body and a lower separate nozzle post member that extends into the fuel chamber of a lower fuel bowl. The nozzle post member has a main nozzle mixing passage leading from a main fuel jet inlet to a nozzle. An annular air passage and an annular idle fuel passage surround the mixing passage. The nozzle post member also has integrally formed brackets to pivotally mount the fuel float.

Carburetor with separate nozzle post member

A carburetor throttle and choke control mechanism incorporating a choke-throttle cold-start fast idle setting latch mechanism having, in a first embodiment, a blade of a fast idle lever specially contoured for creating upon interengagement with a tang on a throttle lever initial torque resistance to co-rotation of the fast idle lever toward latched condition and then effecting force reversal for creating aiding torque to accelerate the fast idle lever relative to choke lever and thereby open a gap in the push coupling that remains in the latched position of the choke and throttle valves. The choke lever has a relatively rigid pusher leg portion adapted for abutment in push relation with a fast idle lever tang. In a second embodiment an extension of the leg portion in the form of a generally U-shaped resilient spring hook portion is adapted to overlap the tang and releasably hook engage the same when the leg portion is brought into full push abutment with said tang. The U-shaped hook portion is resiliently flexible to act as a spring to develop a torque on the choke by pulling the choke valve fully closed when said fast idle lever is moved to fully latched condition while flexing so that the gap remains between the pusher leg portion and the tang.

Carburetor throttle and choke control mechanism

Improvement in peanut clip limiter cap holder, wherein the clip spring legs are interconnected by a spring web that flexes to accommodate flexing of the clip legs free ends during insertion of the associated limiter caps into the retaining clip, and prolongs the effective friction grip service life of the clip. Optional detent dimples on the clip spring legs and cooperative limiter cap grooves enhance yieldable retention of the caps in the clip and the clip on the needle valves. When the peanut clip is used to install only a single limiter cap on a single needle valve, a dummy stud is mounted to the carburetor in the vacant needle valve position and the stud head occupies the vacant limiter cap position in the clip. An improved needle valve is made as an assembly of a lathe-turned tip/shank part and a separate precision die cast head part. The head part has the needle spring stop flange, the fluted spline portion, the limiter cap barb retention structure, and a cavity telescopically receiving a shank stem to rotationally drive couple the shank and head parts in assembly. The shank stem is press fit or cast into the head cavity to permanently join the shank and head parts in fixed relationship, or preferably the head cavity cooperates with the shank stem and a cross arm thereof to form a releasable, telescopic, quarter-turn bayonet coupling. The needle valve spring biases the bayonet coupling to fully locked condition. Coupling axial lost motion insures lock-on of cap retention barbs on the head of the 'shorter' needle, and thus final installation lock-on of both limiter caps while being held by the clip. 'Side-play' between head and shank parts isolates the needle shank part from adverse needle bending moments.

Carburetor needle valve and limiter cap installation and adjustment

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 small engine carburetor with manually controlled choke and throttle valves and associated idle ports and main metering nozzle supplied with fuel from a common metering chamber. The A/F is automatically adjusted by a solenoid operated poppet valve and/or gear driven needle valve and cooperative electronic control circuitry and system components built-in to the carburetor. A combined accelerator pump and idle circuit shut-off mechanism is also built-in and mechanically operated by the throttle shaft so that only the main nozzle supplies fuel when the engine is running above fast idle. A mechanical choke/throttle interlock mechanism also prevents partial choking when the engine is running above fast idle, and throttle operation above fast idle when choking. An electric motor worm gear drive unit controlled by the automatic system is detachably coupled to, and provides fine incremental adjustment of, the main metering needle and is self-locking to retain set adjustment during engine running and at engine shut-off. Control system components are arranged in a compact overall package characterized by a laterally offset, skewed orientation of control box and carburetor body, with a diaphragm fuel pump and metering chamber sharing box and body for intercooling of electronic and electrical components by incoming fuel while assisting fuel vaporization in the carburetor venturi passage.

Growing community of inventors

Caro, MI, United States of America

Eric L King