I'm using one on the Brown B-2 racer shown in the Pic, but only because I have the engine inverted. It's an old solid state unit made by RAM that a friend gave me. I've adjusted it to come on during the lower 1/3rd portion of the throttle, and it works extremely well. I went a step further and replaced the small 1300 sub "C" cell, with a 5000 "D" cell.