It turned out to be the throttle lever adjuster nut. The guy I bought the ATV from must have played around with that nut because the ATV would not run. I bought it from him as a non running ATV. After I corrected the real problem. "clogged jets", I didn't think to check than nut because it should not have been messed with to begin with. Stupid me for not checking that adjustment nut as soon as I put the carb back on. Hopefully this saves someone else from the same bonehead mistake as me.