{"product_id":"16620z8d305-thermowax-thermo-wax","title":"16620-Z8D-305 Thermowax Assembly - Fits Honda HRX217, HRR216, GCV160, GCV190, Engines","description":"\u003ch2\u003e16620-Z8D-305 Auto-Choke Thermowax Assembly\u003c\/h2\u003e\n\u003ch3\u003eKey Features\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePrecision Thermal Activation:\u003c\/strong\u003e Utilizing a heat-sensitive wax element, this assembly automatically regulates the choke plate position based on engine temperature, eliminating the need for manual choking.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOptimized Fuel Economy:\u003c\/strong\u003e Ensures the choke is fully opened as soon as the engine reaches operating temperature, preventing a \"rich\" fuel condition and reducing spark plug fouling.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSeamless Cold Starts:\u003c\/strong\u003e Provides the exact amount of air restriction needed for a reliable first-pull start, then gradually retracts the plunger as the engine block warms up.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHigh-Durability Brass Housing:\u003c\/strong\u003e The wax element is encased in a corrosion-resistant brass cylinder designed for rapid heat transfer and long-term structural integrity in high-vibration environments.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDirect OEM Integration:\u003c\/strong\u003e Engineered to factory specifications for Honda's GCV series, ensuring the plunger stroke and tension perfectly match the original auto-choke linkage.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eReplaces \/ Cross-Reference Part Numbers\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cmeta charset=\"utf-8\"\u003e16620-Z8D-305\u003c\/li\u003e\n\u003cli\u003e16620-Z8D-841\u003c\/li\u003e\n\u003cli\u003e16620-Z8D-842\u003c\/li\u003e\n\u003cli\u003e16620-Z9L-003\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eCompatibility \u0026amp; Fitment\u003c\/h3\u003e\n\u003cp\u003eThis Thermowax assembly is the primary component of the Honda \"Auto-Choke\" system used on premium walk-behind mowers. Key compatible models include:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eHonda HRX Series Mowers:\u003c\/strong\u003e HRX217, HRX217K1, HRX217K2, HRX217K3, HRX217K4.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHonda HRR Series Mowers:\u003c\/strong\u003e HRR216, HRR216K5, HRR216K6, HRR216K7, HRR216K8, HRR216K9.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHonda GCV Engines:\u003c\/strong\u003e GCV160, GCV190, GCV160LA0, GCV190LA.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNote:\u003c\/strong\u003e Specifically designed for engines featuring the automatic choke system located near the exhaust manifold; not used on manual choke models.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eWhen to Replace\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eHard Starting When Cold:\u003c\/strong\u003e The plunger fails to extend, leaving the choke plate open and making the engine nearly impossible to start without manual intervention.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEngine \"Hunting\" or Surging:\u003c\/strong\u003e The Thermowax is partially seized, preventing the choke from fully opening or closing, leading to inconsistent RPMs.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBlack Smoke \/ Sooty Spark Plug:\u003c\/strong\u003e The wax element has failed in the \"cold\" position, keeping the choke closed even after the engine is hot, causing a rich air-fuel mixture.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEngine Dies After Starting:\u003c\/strong\u003e The assembly retracts the plunger too quickly or too slowly, causing the engine to stall during the transition from cold-start to operating temperature.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVisible Plunger Seizure:\u003c\/strong\u003e The metal pin is stuck in place and does not move when the brass body is heated, indicating a internal wax failure.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eInstallation Tips\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eHandle with Care:\u003c\/strong\u003e Do not drop or strike the brass cylinder. The wax element inside is precision-calibrated and internal damage can render the auto-choke system inoperable.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCheck the Linkage:\u003c\/strong\u003e Before installing, ensure the choke linkage and springs are not bent or rusted. A sticking linkage will often mimic a failed Thermowax assembly.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eClean the Mounting Port:\u003c\/strong\u003e Use a wire brush or cloth to clean the area on the engine block where the Thermowax sits. Proper contact is essential for the wax to \"sense\" the engine's heat.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThe Hot Water Test:\u003c\/strong\u003e You can verify the new part's function by placing the brass tip in hot water; you should see the plunger slowly extend. As it cools, it should retract.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAvoid Lubricants:\u003c\/strong\u003e Do not apply heavy grease to the plunger pin, as it can attract dust and debris, eventually causing the mechanism to bind. A light spray of dry silicone lubricant is acceptable if needed.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"BlueStarsParts","offers":[{"title":"Default Title","offer_id":45371210105021,"sku":"AZ10746420","price":9.88,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/2576\/7548\/files\/AZ00136501_1_0bd200a6-83d1-4c11-a03e-1633aeac76bd.jpg?v=1762246290","url":"https:\/\/bluestarspartstrend.com\/products\/16620z8d305-thermowax-thermo-wax","provider":"BlueStars Parts","version":"1.0","type":"link"}