Okay guys, heres the problem. My O.S 61 in my JR ERGO 60 starts, idles, and transistions fine, but after I have been flying for a few minutes and land and start to spool down, the engine stops. I found that it shuts down between 1/2 and 1/4 throttle. I also noticed that it smokes alot. I had to stop flying today because the culdesac started to fill up with smoke. I am using 20% wildcat heli fuel. This is my first glow heli so I don;t know a lot about tuning the engines. Am I running too rich or too lean? I also notice that there are 2 needle valve adjusters on the side of the carb opposite the throttle linkage. Are these the high and low speed needles? Any help would be appreciated.

Yes, they are the high and low needles. Look in the manual or go to the OS website and find the manual for your engine and find the correct needle settings. These settings will get you in the ballpark. The low needle setting the book gives you should be very close, only slight adjustments might be needed. If you have a temp gun that will help with the high needle setting or you can do the finger on the backplate test. After it's been running your target is to put your finger on the backplate for about 3 sec. before it feels like you are getting burned. If it's not hot at all, you are rich. Very hot to the touch, you are lean.

I can't find the manual anywhere on the net. I can't even find the engine anymore.

Try this,
http://www.modelflight.com.au/os-engines.htm

Or this,
http://manuals.hobbico.com/osm/61sx-...-wc-manual.pdf

This is my exact set-up.

As I recall, the 2 needles adjust the high and mid range and there is another adjustment for
the low end. I will look in my book details of the engine set-up if you want. I do not access
to a scanner so I cannot scan then but maybe I can give you some information out fo the
books if you want.

You can also go to the O.S. web site and download the manual for the 61SX-H WC
engine. That should help you tune the engine.

Ok guys, I think I found a manual to it. I will try to tune it later this week. Should there be alot of smoke coming from it or should it be about the same as my 4 stroke 1.20 in my plane?

It should have a noticable smoke trail trail. I would guess that it would be about the same as
the 120 4 stroke. It might be safe to have a bigger smoke trail that the 4 stroke.

Like they said, fly the helicopter for a few minutes and then land it. Feel the engine back plate.
If it is to hot to touch then it is too lean, it should be warm but not hot.