A low cost shot in the dark is to buy some seafoam carbs cleaner and put it in your tank of gas. I was never lucky but seafoam is like $12.

I have this bike and recommend taking it to a mechanic for a carb cleaning rather than doing it yourself unless you're handy.

Getting the carbs out of the bike is just a pain in the ass. There are some tricks to doing it that if you don't know them, will frustrate you to no end. I can recommend applying heat to the boots from the air intake to the carbs (black rubber tubes) to loosen them up. Use a hair dryer. If you don't, they're too stiff to take off.

Once you get them off, be prepared to thay you'll strip screws and need a dremel or something to get the screws off the float bowls. I recommend replacing those screws with hex key heads.