Anything and everything can be repaired, it is just a matter of weather it is cost effective to do it or not.
Now these carbs are made in China, the price of the carb is about 1.5 times the price of the rebuild kit.
Some of the rubber/ plastic bits are destoyed by carb cleaner spray some are not.
Some of the holes are that fine they are barely visible to the naked eye.
Most of the valves are under welch plugs that are hard to get out without damaging the carb itself and a tad difficult to replace properly.
They are made in sterile clean factories because dust in the air can block off passageways.
and you will need a vacuum / pressure gauge to test it properly.
However if you have a curious mind, and enjoy fiddleing with stuff pull it apart.
It ain't working now so you ain't going to make it any worse
Clean every trace of dire from around the carb before you remove it and make sure you plug off the end.
The air passageway does not have any really fine holes but you don't want dirt dropping inside when you pull it down
Go to
http://www.walbro.com/parts-services/ Walbro
While you will not have a Walbro carb, all of them work the same, it is just the size & shape of the parts that vary.
On the page is a video, watch it.
Down the bottom of the same page is a link to the technical manuals
The technical manuals have a detailed coloured series of illustrations showing what is going where for each stage of throttle opening.
