Hmm, I guess I never considered using an amp meter. That would tell everything wouldn't it? I must admit, I am surprised there is nearly no amp draw when spring tension is increased to its maximum.
I found out the hard way that the spring tension I not enough to close the throttle when the servo dies. I made a slow pass over the field right after take off and when I went to throttle up nothing happened, the throttle servo failed at a bit over fast idle. And being an idiot, I didn't have a kill switch. I flew around like than for at least 10 minutes and the throttle never changed. It started raining so I forced the landing and ended up in a bean field.
Never had the chance to experience that I am going to have to check that out never gave that a second thought. What I can remember is in one of my glow planes with a OS 108 in it the throttle died at full throttle and in those days I put big gas tanks in my planes, that was a long and scary flight well over 20 minuets flat out. It all ended well but would not like to experience that again.
Along those two situations, my friend had a DA 170 lose a throttle arm without any spring tension. His throttle just stayed open at just above idle. Well, maybe closer to 1/4. Anyway, when it came off, had he had the spring attached and the throttle went full closed it would have been certain death and complete loss of the entire airframe. As was, he flew for a bit.... got a bit nervous and handed the radio off to me to attempt a slightly faster than normal landing. Uh, where's the kill switch? "Oh, I didn't put one on!" Greeeeeeaaaaat! There was no possible way to get that plane down safely. All to the plane, the owner and the innocent bystanders. Nope, it's best to put it at an altitude that is safe and allows plenty of time for a dead stick approach and let that baby run dry on go-go juice. Needless to say a DA 170 will go a loooong... loooooooooong time on a full tank of fuel and only running at around 1/4 throttle. I think I timed it. Somewhere around 32 minutes. Anyway, I understand and totally respect everyone's experience and views with the throttle spring. I personally will never use them. Low amp draw or not. And secondly, never ever will I put a plane in the air without a kill switch! That is just plane (pun intended) goofy. I think at that point a guy is being knowingly negligent and totally disrespectful to his fellow modelers.
How do you put a kill switch on an YS 1.20 four stroke.
Wow! Somehow I just knew it would be you Snoops that would call me out on that. LOL. Its all good. So, what I used to do with all my Saito engines was this. Actually all the glow (shudder) motors I had. And I "KNOW" you already know this. But since you asked. I set my radio to have a "Throttle" cut just like you would on a helicopter. The program is mixed in with the throttle servo... "Slaved" if you will. A switch on my radio is always devoted to nothing but "engine" kill. Whether it be glow or gas or electric. That way I never get confused when it comes to killing the operation of the motor. It is always the same switch on all my planes. On electric planes, it disables the esc from allowing the motor to run. On gas, it interrupts the ignition signal from the RC Optikill switch. On glow motors, it simply pulls the throttle barrel completely closed and thus, the glow motor dies. Very easy to do.
Ok I agree with you I was just making sure that there was not a new device that I did not know about. But if is a gas engine with ignition then it should have a kill switch.