Needle Valve settings

[janfloris]

Hi.

I have a Kyoho Caliber 3 heli with an Irvine .39 engine. I am very happy with the heli. The only thing I'm not 100% sure of is the correct way of going about setting the low-end and top-end needle valves on a heli. With airplanes you just open the throttle completely and listen to the sound of the engine to set the needle. Is there any tips to set the low end and the high end values of a heli? And also, if you are in a hover and you give a fair amount of + collective quickly, should the engine revs drop as the heli climbs?
Thank you

[BarracudaHockey]

He's got a couple of articles that will help, start with this one.
http://www.raptortechnique.com/enginetuning_beginner.htm

[TheBum]

There's a T-Rex 600 Nitro FAQ started here:

http://www.helifreak.com/showthread.php?t=79343

Even though it's geared toward that particular heli, a few of the questions addressed apply to nitro helis in general. Take a look at the question regarding setting the low-end needle by using the pinch test.

As for the engine revs dropping when doing quick collective adjustments, that's referred to in heli circles as "bogging". Yes, it's normal. There are a lot of discussions in these forums of "collective management", which is a behavior by which you apply only as much collective as needed for a particular maneuver and no more.