I had a 4x2 a couple of weeks ago that the first tech that worked on it just disassembled the carburetor and threa it in the ultrasonic cleaner and threw it back together... Same exact thing... It hunted while foot on throttle and wouldn't idle... He came over and asked my opinion which a responded by asking if hed flow tested it? He said yes... So he did the same thing again: Pulled it, disassembled it, tanked it, reassembled, and threw back on with it doing same thing again... After he left and went home early the boss came out and said he wanted a second opinion because we were way over on hours for this and now losing money... So... I just started all over again because it was still had the symptoms and discovered the following: No flow through the pilot circuit, main jet looked okay, removed the pilot screw plug and pulled it out and discovered some ethanol damager which cleaned up pretty easily... Then discovered the pilot jet wasn't flowing so I used my Honda carburetor tool and my jet drills to clear it... Afterwards I reassembled it up to the point of being ready to install the float bowl, then flow tested the pilot / transfer circuit, and then flow tested the main jet... With everything in order I reinstalled the unit and adjusted the pilot jet to run a little richer... After I got it back together and running there was no more hunting, it idled, and magically that hesitation was gone... It never hurts to clean a carburetor that didn't come in with excessive moisture damage from water or ethanol...