Low-speed optimum setting.
 

After a crash my OS 65LA is running rich on idle.
I know that nothing problem was made to the engine during the crash.
Everything looks fine.
Do you know the optimum setting for the low-speed needle?
I use fuel with 10% nitro, OS A3 glowplug and high-speed needle 360 deggres+45degrees out from fully closed.
Thank's

RE: Low-speed optimum setting.
 

It depends on fuel, air temperature, altitude, humidity, propeller and several other factors, but a general starting point is to let the airbleed screw cover half the hole.

This is how I set the carb on my 25LA:
- peak the high speed needle and turn it back out a couple of hundred rpm.
- let the engine idle, and listen. If it runs very smooth, maybe increases rpms a little and then suddenly quits, turn the airbleed screw IN 1/4 turn and try again. If it gradually idles slower and sounds rough, turn the airbleed screw OUT 1/4 turn.
- you want the idle as lean as possible with steady, but if it increases rpm, dies, or quits when you hit the throttle, you're too lean.

It is very important to set the high speed needle first.

I hope this helps you to get your 65LA running properly. One thing to check (you probably already have, but...) is that the airbleed hole on the carburettor isn't clogged after the crash.

RE: Low-speed optimum setting.
 

In addition to sandal’s method you might pinch the fuel line at idle and see if the engine speeds up. If the engine speeds up it is too rich.

Bill

RE: Low-speed optimum setting.
 

Check to see if there's some dirt blocking the airbleed hole in front of the carb after the crash.

RE: Low-speed optimum setting.
 

It's ok.
I checked it.

RE: Low-speed optimum setting.
 

Hi!
If it's running rich at idle ...just open the airbleed screw some and see what you get!! it's that simple ...;)
The airbleed needles on the OS engines are non critical and could be set within a wide margin and still work just perfect.


Regards!
Jan K