Products Description
Walbro WYC-7 Carburetor for Brush Cutter GST33 | Diaphragm Carb Assembly for 33 cc 2-Stroke Grass Trimmers & Clearing Saws
Precision-Cast Alloy Body with Adjustable High/Low-Speed Jets, Integrated Fuel Pump Diaphragm & Butterfly Throttle Valve
Brush Cutter Walbro WYC-7 GST33 carburetor small hole
The WYC-7 features an adjustable high-speed and low-speed jet circuit, allowing precise tuning of idle mixture and full-throttle fuel delivery to match altitude, temperature, and fuel quality. The cast aluminum-zinc alloy body resists the ethanol corrosion and thermal warping that plagues plastic-bodied economy carburetors. Common failure symptoms that this replacement addresses: hard starting when hot, bogging under throttle, surging at idle, fuel dripping from the overflow, and no-start after seasonal storage - all traced to a tired pump diaphragm, clogged metering screen, or varnished jet orifice in the original carb.This design operates reliably at any angle, making it the standard for handheld outdoor power equipment that runs sideways, upside-down, or on steep slopes.
Technical Profiles & Materials
Adjustable High & Low-Speed Jets - Tune for Altitude and Fuel: Two externally accessible adjustment screws control the fuel circuits: the low-speed (L) screw sets the idle and transition mixture; the high-speed (H) screw sets full-throttle mixture under load. Factory baseline is typically 1.25–1.5 turns out on both. At higher altitudes (>1,500 m), lean the H screw slightly to compensate for thinner air. On ethanol-blended fuel, a slightly richer setting prevents the lean-run piston damage that ethanol's oxygen content can cause.
Diaphragm Fuel Pump - Works at Any Angle : The carburetor's bottom plate houses a pulse-driven fuel pump diaphragm. Engine crankcase pressure pulses - alternating positive and negative with each piston stroke - flex the membrane, creating a pumping action that lifts fuel from the tank through the inlet nipple into the metering chamber. No gravity feed required, no float bowl to flood at an angle. This is why brush cutters, chainsaws, and pole saws all use diaphragm carbs.
Technical Specifications
| ITEM | DETAILS |
| Type | Diaphragm Carburetor - Walbro WYC-7 Series |
| Application | 33 cc 2-stroke brush cutters (GST33), grass trimmers, clearing saws, 26–43 cc handheld outdoor power equipment |
| Code | 2301230 |
| Material | Die-cast aluminum-zinc alloy body, ethanol-resistant diaphragm, brass jets & adjustment screws |
| Details explanation | Adjustable H & L speed jets. Diaphragm fuel pump. Butterfly throttle valve. Venturi bore: factory-calibrated. Fuel inlet nipple (left), return/overflow nipple (bottom right). Direct bolt-on replacement. |
| Brand Name | SeaSummer |
| Operating Temp | −20 ~ +120 °C |
| Delivery Time | 30 Days |
| Packaging | Cardboard packaging |
Products Application
Ethanol-Damaged Carb Replacement
The most common root cause of WYC-7 failure is ethanol-blended fuel left in the carburetor over winter storage. Ethanol absorbs moisture, corrodes the aluminum fuel passages, swells the pump diaphragm, and leaves varnish deposits in the metering orifices. A replacement carburetor is often the most cost-effective repair path - especially for commercial landscaping crews who need the machine back in service the same day and cannot afford the labor time of a full teardown and ultrasonic cleaning. Install, tune the jets, and the trimmer is back on the truck.
26–43 cc General-Purpose 2-Stroke Equipment
Beyond the GST33, the WYC-7 bolt pattern, venturi diameter, and throttle linkage interface match a broad range of 26–43 cc 2-stroke engines powering straight-shaft trimmers, pole pruners, hedge trimmers, and mini-tillers sharing the same carburetor mounting footprint. For repair shops and equipment dealers, one carburetor SKU services multiple machine types across the small-engine displacement band.
33 cc Brush Cutters (GST33 & Compatible Models)
The primary fitment. The GST33 is a widely sold 33 cc straight-shaft brush cutter platform - used with nylon trimmer heads for grass, and steel blades for brush and saplings. The WYC-7 carburetor is the factory fuel system on these machines. When the original carb develops the classic diaphragm-carb failure cascade - hard hot restart, bogging under load, surging idle - a bolt-on WYC-7 replacement restores predictable starting and clean throttle response without the trial-and-error of a rebuild.
Quality and Craftsmanship Details
Products Package
About Us
As a premier garden machinery parts supplier, Jiaxing Norsun Trading Co., Ltd. bridges global distributors with over 100 vetted China manufacturers. We streamline your B2B supply chain through strict quality control, flexible production, and factory-direct wholesale pricing. Partner with us for reliable, high-volume sourcing of precision-engineered outdoor power equipment components.
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YOUR PROFESSIONAL ONE-STOP SOURCE
FOR 10000+ OUALITY PARTS
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BACKED BY 200+ TRUSTED FACTORY PARTNERS
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FAQ
Q: Are you an impartial industrial components dealer or a direct China water pump factors factory?
A:We are a direct, ISO9001-certified engineering water pump components manufacturing facility and precision fluid-control factor manufacture exporter primarily based in China. We function our personal cleanroom injection molding bays, computerized ultrasonic welding arrays, computerized hydraulic stress check stations, and clean-room packaging lines, passing direct-factory wholesale price financial savings straight to your element procurement margins.
Q: Can your manufacturing unit furnish full certification forms for food-contact or consuming water compliance?
A: Yes, absolutely. For food, beverage, or scientific applications, our manufacturing unit makes use of one hundred percent virgin, un-recycled polypropylene resins accompanied by means of fabric traceability certificates. We mechanically furnish B2B purchasers with complete FDA compliance documentation, NSF-grade compound declarations, and RoHS/REACH chemical protection screening sheets to make certain clean clearance thru worldwide customs.
Q: Do you provide customization picks for distinctly corrosive fluids like sturdy acids or ozone?
A: Yes, we are a thoroughly succesful OEM/ODM supplier. For aggressive chemical or ozone environments, we can improve the 12x26.5mm valve configuration in our factory: substituting the general PP housing with top class PVDF (Fluoropolymer) and changing any steel springs with Hastelloy or whole springless gravity-ball architecture, making sure final chemical resistance.
Q: How do we impervious a pattern batch to execute computerized lifecycle and burst-pressure testing?
A: We relatively inspire complete laboratory contrast earlier than logging mass grant agreements. We can ship a pattern lot of 5-10 gadgets of our inventory 12x26.5mm take a look at valves for assessment (setup costs and DHL/FedEx air freight apply). Once the factors pass by your inner lifecycle verification and a formal wholesale quantity manufacturing contract or container run is locked in, the sampling charges are a hundred percent credited returned to your industrial balance.
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