Welcome to the board Chris, you will find it very informative. If you aren't sure yet what you are doing just take your time and do your home work before starting to mess with the carbs. The 550 is a rugged design and is somewhat forgiving. If it is running well and idles fairly good you probably are not going to hurt anything. I ran a Mac 4into1 for years on my 75 550K with the stock carb setup and never had any issues.
Now first things first. If you haven't done so yet you need to do a complete tune up, plugs, points, timing, cam chain tension, valve adjustment, and air filter. This will eliminate a lot of other variables and get things right with the engine. Only then should you start worrying about the carbs. Next go to the FAQ forum and search for "plug chop" or "reading the plugs" and then perform the plug chop as described. The color of the plugs will tell you if you are running lean, just right, or rich. There are some color charts/pictures there I believe that will guide you. Only after you know how your carbs are actually running should you think of tearing into the carbs. If that is still necessary then again go to the Carb FAQ or search on rebuilding the carbs. Been discussed many times.
Good Luck.
