The first place I would start looking would be your aircleaner/filter. Ensure it's clean, and no obstructions. Second, I would remove the airhorn from the throttle body and while the engine is at idle, spray some throttle body/carb into the throttle body. Be prepared to grab a handfull of throttle to keep the emgine from stalling out when spraying. Then, I would run up the rpm's some and spray a couple more shots. After that, add fuel injector cleaner to your gas tank and then everyother tank, add a fuel addivtive that removes ethanol. Ethanol alone, is the ring leader for 90% of all carb/injector issues.This crap really gums up things and provides for symptoms you discribe. It may take a tank or two to clear up but, if caught sson enough and then follow prevenative measure's, you should be ok.