WAY TOO LEAN!!!!

You are cooking the motor, you need to open up the needle some.

You should not need to play with the mixture during the day. Once, maybe.

The reason it dies, it becasue it leans out in the air and that is the reason the head to turning brown.

When you adjust the needle on the ground, use the pinch test. Pinch the fuel line. If the RPM's drop, you are too lean. When the motor is propperly tuned, when you pinch the fuel line, the RPM's should jump up. Leave it there, do not adjust any more.