i heard thru the grapevine that a common cause of a low idle (not rough, low) is that the TBs are dirty. i imagine mine are probably dirty, 1 because the motor has almost 61k on it and 2 because it idles a lot slower than it used to, sometimes as low as 500rpm. i'd like to know if anyone has serviced their TBs and how they did it. thanks in advance.