My 154 Cub-Loboy won't run at 800- to about 1,100 RPM.

My 154 Cub-Loboy won't run at speeds between 800- to about 1,100 RPM. It idles great at around 500-525 RPM ( I know the book says 475 RPM) and the the max idle speed is around 2,200 RPM. (I know the max is about 2400+-). My RPM gauge could be a little off too. It starts with no choke and has plenty of power. It accelerates great. It runs great with the exception if I set the throttle into the 800- 1,100 RPM range, it goes BLAAAAAAA and will stall right out (even if it has been running an hour. I have to choke it to re-start it. I can go from high idle to low idle with no problems. Any ideas? I put an IH carb kit in it last year and set the float hight and drop to spec. I also have a Fram G3606 inline filter that I just replaced. I have used this type of filter on this tractor for years. Thanks!!

At that engine speed at an idle or when a load is on it or put on it?

John I also own a 154 and have had a this hapen to me. Check the coil and points also the wireing between the coil and distributer. This may help