I have a new to me 1988 Trailboss250 2x4. It will start and idle just fine.When you start to take off,it does not run real clean up to about half throttle. Above that, up to full throttle it runs strong.I have cleaned the carb and moved the clip on the jet needle up and down one notch without any improvements.Also,I can't seem to tell much difference with the choke on or off. I have adjusted it and it seems to be doing what it is supposed to.Like I said before, it will start and idle just fine. Any help would be welcomed. Thanks