Using the throttle is of course the easy way to kill the engine. ANYONE flying ANY RC wet-powered model should be able to shut the engine down at any time using the throttle.

Now in RC Combat, you will find that most competitors use a CL type needle-valve only for fuel along with a "pen-bladder" type tank. That is very HIGH pressure and the cut-off is simply a small servo that releases or moves a spring-like wire that compresses the fuel line to reduce the engine fuel supply sufficiently to kill the already maximum-lean engine.

You should attend a sanctioned RC Combat event and you can see a number of different arrangements. Nothing like association with the active to get an education. Hey, I did that just this past Sat. when I entered my first Club 40 Pylon event, Heck, someone has to be last. I use to fly a lot of Pylon back in the late '70s and early '80s.. That did NOT show this past Sat. [sm=cry_smile.gif]