2006 Honda trx 350 not ideling when cold. When warmed up runs grand. What would be the issue

 

They don't, most carburated engines only idle properly when warm. Unless freezing the old 300 would idle like a swiss watch from cold but 350 on the same carb needs choke and idles badly on part choke until it starts to warm up. You can increase idle speed a bit, but too much, and the centrifugal clutch tries to engage all the time when warm.