I was kind of in the same situation when I got my '79 CB650. Bought it off ebay HOPING that it wouldn't need any serious work. Got lucky and all it needed was a battery, rotor, and carb cleaning. Carbs would be the first thing to look at, then check spark. If the motor turns freely and doesn't make any strange noises, that's probably all you'll have to do. Welcome to the forum and good luck on your project!!