Hi centexn, welcome to Outdoorking.
The GCV160 carburetor is mostly the same as the one on the small GXV engines, and the idle speed screw is in much the same place. It is circled in red in this illustration from the GCV160 shop manual:
![[Linked Image]](https://www.outdoorking-forum.com.au/forum/uploads/usergals/2013/08/full-2772-12005-honda_gcv160_idle_speed_adjustment.png)
At a guess, when you rebuilt the carburetor you may have turned this screw all the way in, which would give you a very high idle speed. Note that the screw has a spring underneath its head, to keep it from rotating on its own when the engine is vibrating. Just turn the screw anticlockwise until the idle speed is correct (1750 rpm).
This will be enough to fix the problem if my guess as to the cause is correct. If that is not the problem, please come back and we can check for some more complicated problem, such as a fault in the choke system.