I have several planes, some will not kill the engine when I use the kill switch and some do. This happens on both of the transmitters which have 6 planes each on them. I have not found why some work and some dont, I suspect ity has something to do with the trim seting of the throttle. Anyone have any experience with this? Does the throttle trim have to be set to zero or very close to zero for it to work?
Denny

The first question is what radio? With mine, Futaba 6EXA, I don't need the throttle trim all the way to zero to kill then engine. However, when I'm setting up the plane, I do confirm that the engine cutoff completely closes the throttle barrel. The nice thing about the throttle cutoff switches is that they leave your trim set to the appropriate idle level.

One cause of engines running on after shut-off is an air leak, especially where the carb mounts to the case. Check that it's seated firmly and that the o-ring, if present, is in good condition.

Ditto on what Chuck said, I also have a kill switch so trim movement is not needed.
When I'm setting up my throttle linkage I zero all imputs on the radio and set the
throttle stick in the center and checking that the servo is centered.. I now check
travel against the hole/s on the carb. horn<??> and make what ever adjustments
that are needed... I usually input 100% on the kill switch in the radio set up.. I then
close the throttle stick and push and hold my kill switch then shut off the power on
the radio and plane. I then close the carb. completely and hookup the linkage, and
recheck and adjust as needed....
I started all my adjustments the same way on my non-kill switch radio radio.....

I don't have a kill switch, but I always set my throttle throw to kill the engine. I set a "normal" idle around trim center, then adjust it so the low setting kills the engine. Since the normal idle is around center, I have idle adjustment leeway both ways.

Dr.1

What Dr1Driver said.

Everyone does it a bit different… this is how I do mine

First thing you NEED to do is set the servo mechanically… using 100% end point and trim centered, adjust the servo linkage so you have full open and full close or as close as you can get it… one mistake a lot of us make with computer radios is not bothering with mechanical set up… why bother when you have end point, trim, sub-trim and so on… if you don’t you can run into to problems that’s why Once I’m set up mechanically I use the end point to open up the carb enough for idle… say 2mm. Then I start and tune the engine… now I use the end point to set the idle I want. Then I set up my throttle cut so the engine shuts down every time and add 5-10% on top for good measure… even if you’re over driving the servo with the extra few % it’s only for a split second and hasn’t hurt any of mine yet. By doing this I can always shut down my engines and still have some head room for adjusting Idle with trim due to tuning changes.

John

Tenacious,
Are you at idle when you hit the kill switch?
My Hitec Flash V won't allow the kill to work above a certain speed.
Prevents accidental kills while in flight.
Good Luck,
KW_Counter

Tenacious, I have my kill switch on my Futaba 7C set on the switch normally used as the trainer override. It's spring loaded so if you accidentally bump it, the engine won't cut off...you have to hold it for a couple of seconds to kill the engine.
Bev

Any transmitter will kill the engine if the throttle barrel can close enough to stop the engine.
You just have to adjust it so that it will work with either a switch or the trim tab.