Re: idle
1200 is way to high, should be in the 650 to 700 rpm range. My first question would be WHY is it idling that high? Did it just suddenly start, did you do a tuneup or something?
May be the cable is going bad on you and not allowing the carb to come all the way back. Thing to do there is disconnect the cable and see how it idles
If you look at the linkage on the carb where the cable attaches, down on the base of the carb or on the linkage is a screw that adjusts the speed.