RE: Erratic when warm! (YS 110)
I never try to get one to idle at 2000. 2200 to 2400 is more reasonable and easy to get.
The overheating issue is something else. It could be the fuel, or it could be that you just have the top end set too lean. Have you adjusted the regulator? If not, it may be set too lean as well. Try opening it 1/2 turn and let me know what happens.
Dave