Sorry it took me so long to reply. I was away from my computer for a while.
The fuel pump kit is a good deal for preventative maintenance. Not very expensive and really quite easy to do. You should note that the fuel pump pumps gas from the tank to the carb. It has NOTHING to do with getting it into the combustion chamber...
The carb is a little more complex. There could be many things wrong and one of the best ways to determine what is causing your problems is a full disassembly of the unit.
What I usually do for an engine that was running great but isn't now is to take the carb off and disassemble it (remove the bowl, needle, float, all set screws, etc...). Put the whole mess of things in a container with some carb cleaner or deisel fuel. Carb cleaner generally works better, deisel is cheaper. Let it soak for a while.
After all the crud is gone, you can usually see any parts that are worn. From there, I replace anything that looks worn and re-assemble. After adjusting it, I usually find the problem is gone. Carbs are tricky. Any little piece of dirt around the needles can send things into a tailspin.
Also, I would re-build rather than purchase. A full carb re-build kit is probably MUCH less than a new carb and you're mainly paying for the body when you get a new one. Chances are, that's the one part that will never break.
Take your time and if you have questions, post some pictures if possible with descriptions of what is wrong. I'm sure someone here can help you through it!
Have fun!
Mark
