The MTD 951-14028A Carburetor Assembly Primer Hydraulic helps deliver the proper fuel and air mixture for reliable engine operation. This carburetor assembly meters fuel, combines it with incoming air, and supplies the mixture to the engine for combustion. Its primer mechanism assists in preparing the fuel system for starting by helping introduce fuel into the carburetor. Proper opera... https://www.wholetoolbox.com/mtd-951-14028a-carburetor-assembly-primer-hydraulic/951-14028A.html