New carb install after buying the ATV from a friend. He ran ethanol fuel in it and gummed up the carb so for $25 I just put a new one on it. It’s cold natures so it takes a little while to get it to run and sometimes it runs and idles fine but most of the time it idles like I’ve got the throttle bottomed out and won’t idle down. It still does it with the throttle speed backed down. When it is running okay I tried screwing down the throttle so the kids could try and ride it and even with the minimal amount of throttle over about 10 seconds it starts to rev really high but will idle down eventually. This is only when it’s not being temperamental. As of late it only cranks and revs really high. Any ideas to help me out? I run 93 non ethanol fuel in it. All new fuel lines when I installed the new carb.

 

Try cleaning out the old carb properly and re-fitting it. I do this by removing jets and cleaning them, and the passageways they came from, out with an airline. I don't alter mixture settings. Can't hurt to try it. Check there is some free play in the cable too.