What this part does Carburetor designed to control the fuelair mixture for reliable starting, steady idling, and consistent engine power in compatible Echo backpack blowers. Key benefits — why you need it Restores performance: replaces a worn or damaged carburetor to eliminate hard starting, poor throttle response, or uneven running. Directfit replacement: made to match the original carburetor mounting and interface so you can the old unit without modifying the blower. Reduces downtime: keeps professional and homeowner equipment back in service quickly. Compatibility (exact models and part numbers) Suitable for Echo PB770, PB770H, PB770T backpack blowers. Replacement for Echo part numbers A021001870 and A021003940. Compatible with Walbro/WYK series: WYK406, WYK4061, WYK345, WYK3451. Important attributes Function: carburetor for fuel/air regulation and engine performance. Fit: intended as a direct replacement for the listed Echo and Walbro/WYK part numbers and blower models. Performance: restores proper fuel delivery to improve starting, idling, and throttle response. Installation and use notes the original carburetor with this unit when you experience starting difficulty, surging, or loss of power. Follow manufacturer's service instructions or have a qualified technician install and adjust the carburetor to ensure correct jetting and idle settings. Typical use scenarios 1. Homeowner : a failing carburetor on an Echo PB770 backpack blower to restore reliable operation for seasonal yard cleanup. 2. Landscape professional maintenance: Keep a replacement carburetor on hand to quickly service PB770 series blowers and minimize job interruptions. 3. Equipment restoration: Fit this carburetor when refurbishing an older PB770, PB770H, or PB770T unit to it to dependable performance. Compatible with the exact models and part numbers listed. Use appropriate safety procedures and follow service instructions when installing.