I have a 1972 250 with some annoying carb issues. Please post any thought you have on the problem/cause.

I bought the car 5 months ago in Denver, it had not ran for some time, but I worked through it and got her on the road. She was running great for the first two months until one hot day. Somthing clogged the idle jet on the front carb and from there the performance went down hill. I have performed the following things. New fuel filter, cleaned the line and carbs out side and, removed the top and cleaned the jets. Car runs better now but is hesitating off the line. Cold start is hard, hot start is not so great, and warm start is problematic. Once the RPMs get above 1,500 runs like a champ, but she "chuggs".

I think that the problem is still carb related, because I have spent a lot of time making shure that the ignition is perfect order. Please help with any advice that you have.

Thanks