I have a DA 100 which has 3 gallons of Lawnboy and 2 gallons of Pennzoil 32-1 run thru it. About six months went by without running it. Today when I ran it, the top end is good but the idle was rough and would not reduce down like it used to without quitting. I had to richen it to get it lowered but then it loaded up and sputtered in transition to high end. I'm sure the carb needs cleaning. Besides the screen needing cleaning, is there a low end carb jet that I need to clean? Your help would be appreciated.