@Ernie... the spring works!

[Doozer]

I was hovering my gasser in the cul de sac at the end of my street and couldn't hear my Tx beep due to low battery. Luckily I was only a few inches off the ground when the tx powered off, but because of the return spring on my throttle, the throttle closed, the engine shut down and the helicopter floated nicely to the ground. Without the spring, the motor would have kept running and would have led to all kinds of bad.

There were some lessons learned here i.e. pre-flight checks aren't just for the helicopter but the tx too; flying in the street, albeit the end of the street where there's no traffic, is just not a good idea; the return spring on the throttle works as intended and saved the helicopter from running amuck in a no power situation.

Zenoah engines come stock with a return spring on the throttle. I was about ready to pull the spring off too. I was worried that it was putting too much stress on my throttle servo. Glad I didn't. Thanks for input Ernie. It's Great advice. Needless to say, I'll be leaving it on.

[McKrackin]

Are you sure it wasn't the failsafe?
I wouldn't think the spring would pull against a servo with power to it.
It's more for if the heli RX loses power.

The amount of stress on a throttle servo with a spring is miniscule compared to a tail servo or even cyclic.
They have pounds on them while a spring is less than a half ounce inch.

[Doozer]

It's my understanding that the 9303's fail safe and the 921's fail safe(smart safe) only changes the position of the cyclic servos to where they were when bound on a Tx power loss. It doesn't change the throttle servos position, but cuts all input. So the if the spring wasn't there, the servo would have stayed in the same position. At least that's the way I understand it.

[McKrackin]

That makes sense.
I set up my fail safe at an idle instead of cut off.
If it loses signal for a few seconds,it would be nice if the engine was running if I get control back.

A nitro won't do any more damage at an idle than it will dead in the event of a dead stick crash.

If the impact throws a link...spring time.lol....

[Doozer]

I've done a couple of stupid things with the gasser. I've started it without power at all, thinking I had plugged it up. That time the throttle was at mid stick I burnt up the liner holding on to the grips, and there is this times, "I forgot to check the tx battery" issue. Both had happy endings, but both had the potential to be very bad.

My gasser weighs in @ 12 Lbs. If I lose power and I'm not up high, there isn't much chance of a recovery... not for me anyway, I have the "I smoked a lot of mother nature in the 70's and 80's" reaction time. I haven't thought this all the way through, obviously, but in this case having the spring on was a heli saver.

[McKrackin]

I've started it without power.
Started it in idle up.
Started it with a dead RX battery.

No crashes but one smoked clutch liner.

Now I have a Switchglo Pro and GLOve chip so hot starts are impossible and the plug won't light without a good RX battery.

It has audible tones for "good glow plug" and "plug lit".
The GLOve chip disables the Switchglo if the throttle is no on 0%.
It also automatically lights the plug after the crank turns 2 times in 1/10 of a second.
That's almost the same as electronic ignition.
I put in the starter and start cranking.It's all automatic.

It also lights the plug at low RPM's to prevent stalls.

The GLOve eliminates all radio mixes.