Also,since you just bought this motor, open up your drain plug on your lower unit and see what the gear oil looks like. If it's sort of thick, gooey and milky looking (not very translucent at all) it means you got water that leaked into the lower end. Marine gear oil is made to emulsify with water, that way it can still continue to lubricate and will prevent your lower end from eating up the gears or seizing. If you find a leak they also make kits to replace the seals on your lower end. It's a bit more complicated than doing and impellor change, but it's NOT rocket science either. Just pay attention to the way the old seals are positioned when you are taking it apart. Go to marineengine.com, punch in your model number or serial number of your engine and they will display an exploded diagram of your engine (or lower end, or whatever you select on the menu) that will help with disassembly, reassembly and part number identification.. Do you have a maintenance manual for your engine?