I have a Kyosho Nexus, and I would like some help
on putting a throttle spring on it so if my heli crashes, and
the throttle arm to the servo pops off, it wont run
my engine wide open, this sprng would close off the thrttle
and kill the engine.
Has anyone done this before? And if so, could you recommend what type of springs would work?
All help would be greatly appreciated.

The same spring RC car guys use.

Thanks a lot.

With all the technology thay have today you would think thay would be able to design a carb that will close when the link falls off,not open. I would think thay would do it for safety if not for anything else. Whats up with that anyway? I'm sure there is a story why thay do it that way?

. Manufactures don't want to take the extra time and money to do something like that. And besides, it would be horrible luck if they actually made money if you destroyed your engine and had to buy a new one from them (sarcastic).

I think a carburetor the MFG would have to design wouldn't be worth the extra cost. $1 added cost can be a lot in manufacturing sometimes. Manufactures aren't concerned about safety. They are concerned about making money. Their lawyers are concerned about safety, that's why you get disclaimers and instruction manuals. If the MFG thought that adding a closing carb would gain them money then they would add it and you would see a marketing add about it.