Picked up a Giant-vac tailgate vac this weekend, it is older I'd say anywhere from 5 to 10 years old, but it has like 100 hours on it. Anyway it starts and runs perfect except for the fact that it has to be at half choke. Is this a carburetor adjustment? If I open or close the choke more than half it will start to bog almost immediately and then shut down all together. I can do all kinds of engine work but my dad and I have never had any luck with carburetors. Help me out and let me know if its a carb adjustment or I need to put a rebuild kit in.