Let me try to heelp. After break in, the engine loosens up and sometimes either idles too high or too low. There are three needles.

*First, the idle needle, this is the one located under the air filter foam element. It is unlikley ever touched. It should be set to factory, the flat blade screwdriver slot should be horizontal with the car body.
*Second is the low speed needle, located at the bottom of the carb body facing out, this screw head should be "flush" with the carb body. Good way to test this is to put the car on a box or stand so the wheels are off the ground. Once started, set the screw so the car idles and stays running without the wheels turning. Turn to the left is a slower idle, turn to the right is a faster idle. This also affects off line power.
*Third is the high speed needle, the one facing up on the carb. With the car off, turn it all the way in to "close" position, from there, turn it out 3 turns, this is the factory setting. Start the car, you should be runnning it about two to two and a quarter turns out from closed position. You will adjust this needle to richen or lean the car.

If the car is stalling out, try turning the high speed in a little bit clockwise to lean it out. Depending alot on the hot or coldness of your glow plug, keep the car between 185 and 240 degrees running. Hope this helped a little.