Chainsaw Repair

My 5105 bogged in the middle of felling a tree, thought I was out of fuel. Opened tank and topped off and restarted, From mid throttle up it would accelerate to top speed. Finished the cut with another Dolmar and took the 5105 to my local dealer/mechanic. He couldnt figure it out and tried a carb from a known good running saw and it ran fine. He put a new carb on it sharpened the chain and charged me $99.66. I asked why he didnt clean the carb and he said he cleaned as much as he could but the adjustment screws are sealed. How do you remove the EPA dont adjust this plugs?