How Much Can A Used Fishing Rod Lift?

Generally speaking , the length of the used fishing rod that you bought should give you a good approximation of the weight that you can lift with it.

Here are some relevant paragraphs from http://en.wikipedia.org/wiki/Fishing_pole

Each rod is sized to a particular weight of line: larger and heavier line sizes will cast heavier, larger flies. Fly rods come in a wide variety of line sizes, from size #0 rods for the smallest freshwater trout and panfish up to and including #16 rods[1] for large saltwater gamefish. Fly rods tend to have a single, large-diameter line guide (called a stripping guide), with a number of smaller looped guides (aka snake guides) spaced along the rod to help control the movement of the relatively thick fly line. To prevent interference with casting movements, most fly rods usually have little or no butt section (handle) extending below the fishing reel. However, the spey rod, a fly rod with an elongated rear handle, is often used for fishing either large rivers for salmon and steelhead or saltwater surf casting, using a two-handed casting technique. See Fly fishing.

Ultra-light spinning and casting rods are generally shorter (4 - 5.5 feet is common) lighter, and more limber than normal rods. Tip actions vary from slow to fast, depending upon intended use. These rods usually carry 1 to 6 pound (4.5 to 27 N) test fishing line. Some ultra-light rods are capable of casting lures as light as 1/64th of an ounce - typically small spinners, wet flies, crappie jigs, tubes, or bait such as trout worms. Originally produced to bring more excitement to the sport, ultra-light spin fishing is now widely used for crappie, trout, bass, bluegill and other types of panfish.