I saw on another thread the following:
"take the plastic cover of the top of carb, with a pair of diaginal cutting pliers break the aliminium of around the mixture screws. Take your time. Then unscrew the
mixture screws and don,t mix them up they are different sizes.
shoot some carb cleaner into the holes. put the screws all the way back in until they bottom out and them unscrew them 1.5 turns out to start. put cover back on then fire her up. you can fine tune the jets by screwing them in 1/4 at a time until it runs
clean at full throttle. if it runs clean at full throttle and won't keep idle back the screw closest to the engine back out 1/4 turn at a time until idle is ok. This fix works on all carbs with EPA screws. SWEET!!!"
I can't give credit because I lost the thread and only have what I copied to print off. I will be trying this in about an hour.
HandyAndy, September 2009