Part 631021B, Carburetor Repair Kit, is a genuine OEM part manufactured by Tecumseh. The manufacturer describes it as "INLET NEEDLE KIT". Tecumseh carburetor repair kit. If the carburetor is clogged, the engine won't get enough fuel. As a result, the engine may not start or may run poorly. It is used in Toro String Trimmers. Prior to rebuilding the carburetor, we recommend that you clean the carburetor's jets with carburetor cleaner. Find appliance parts, lawn & garden equipment parts, HVAC parts and more from the top brands in the industry.