Fast Idle

[Racer1955]

Bought a used Trailmaster XRX for grandkids. I had to replace the carburetor
and got it to start and run. When u start it up the idle is fine and you can put it in gear with no problems. After it has warmed up the ide increases to much where you can't put the cart in gear without grinding the gears. There is one screw on the carb which i have no idea what its for but its not for the idle.
The throttle cable is not sticking and if i push the throttle by carb all the way over it does not slow it down. Any suggestions would be appreciated

[x-bird]

sounds like one of two things,
fuel enrichener aka (auto choke) is not closing. this is the part of the carb that has the wires going to it. it provides extra fuel while cold then closes that feed off when warm.

someone also might have adjusted the float to compensate for dirty pilot/ part throttle jet so it would hold idle when cold by drawing off the main circuit with what would normally be a too high of an idle position.

TBH, either or these issues or anything carb related with these, a cheap ebay carb is a quick and inexpensive way to get back running vs the time it takes cleaning and testing 3-4 times to resolve the problem. i don't even hesitate replacing them any more.

[Racer1955]

I did put a new carb on. That is another problem could never get the choke to close all the way. Spent hours on trying to modify the choke cable bracket with no help. I now just give it a shot if either. It starts fine and idles good but when warm up idles to fast. Kind of end ideas. When it gets warmed going to try to find someone that works on these. Thanks for response.