I have two DLE 170's in two 40% planes. They both have the same issue of running rich on low end. When I adjust either one of them to where they have a smooth low end they are so lean they wont start. When I richen them up a bit they start but have that annoying burble I cant stand. The first one I change the carb, ignition, the battery, set the timing to both ends of the slotted spectrum that you are able to adjust but still have that burble. Any thoughts.