The purpose of the Fuel Pump is to propel fuel from the gas tank into the engine. Equipment jerking during operation, engine sputtering, losing power when accelerating or going uphill, might all be signs that your fuel pump is going to fail soon. The fuel pump usually mounts on the side of the engine and a replacement is relatively easily to install with a screwdriver. Older style metal fuel pumps may have the option to be rebuilt, but new plastic ones must be replaced if they fail.