I am at my wits end. I cannot get the RPM on this Honda GCV160 to go down. I have adjusted the idle screw and the governor arm. I can't get it to reduce. Here's what I'm talking about
You've tried loosening the governor arm? Did you go the wrong way with it? Just thinking about what could go wrong.
https://cf.hondappsv.com/files/OP/OP000011GLOBAL/2010_11_08 General GCV135_160_190 GSV190 Engine Adjustment I.pdf
Found a video that might help.
I tried moving the arm while running. Didn't change. I was messing around with the carburetor bolts while it was running and when I loosened them, It seemed to drop a little. When I put the air filter back on, it ramped back up.You can also move the throttle control arm manually with your hand, not with the throttle cable, while the engine is running. This can tell you if the engine responds to arm movement, and where the arm needs to go to reduce RPM. On my old GCV160 there are a few different arms & springs that move together and if any of them are cattywumpus it doesn't work.
If all else fails then you may have a governor issue. It may be broken & need replaced.I tried moving the arm while running. Didn't change. I was messing around with the carburetor bolts while it was running and when I loosened them, It seemed to drop a little. When I put the air filter back on, it ramped back up.