I've been using a servo controlled choke on my gas engines for years and they always stop. Actually I've never had to resort to using the choke to stop an engine because I make sure that my throttle travel closes the butterfly all the way when I use the throttle cut function on my radio. It's never failed and works just the same with a glow engine. I've been flying gas for 6 yrs, 23cc, 50cc and 100, and never felt the need for any expensive kill switches. JMHO