I am going to guess that there is a partial blockage in the carburetor. You might get by with putting some carb cleaner in the tank and letting it work thru. If not, a teardown of the carb and thorough cleaning are called for. Not hard at all, just have to be careful to pay attention to the way things come apart. Keep us informed!
Yes, but just think of the fun and satisfaction you'll have putting it in, and stepping back after you're done and patting yourself on the back for a job well done. Not in a vain way, of course. Priceless.
But to make you feel a lot better, just as a comparison, I put carb kits in a Honda motorcycle I owned quite a few years ago. Four carbs, all the parts could be held in your hands...$300.00! But it sure ran better afterwards