Clean it real good in and out with carb & choke cleaner first. Make sure your auto choke is set to no more than the 1 notch rich, the black housing on the left side of the carb. If you have to adjust it just loosen the screws, don't remove them, and slightly turn the housing. Once it starts cold you can then adjust the auto choke mechanism on the right side of the carb if it's working properly. It should never high idle at 3000 rpm's. The setting should be no higher than 2000-2200, then it should kick down to about 1500 before idling hot at approx. 800 rpm for these carbs. You might have linkage hanging up that's why I recommend to clean it first.