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.