In order to diagnose the problem we need some more info.

1. What type of fuel are you using and how old is it?

2. Do you return any of the unused fuel back to the bottle?

3. When you adjust your needles do you go mad crazy with them or turn them equivalent to 1 hour on a clock face?

4. Is your pressure line securely attached and how long is it?

5. Do you wait until the motor is warm to start adjusting...should give it about 1/4 tank of use to adjust and adjusting at 1/2 tank is ideal because it will tend to run slightly lean when near empty and slightly rich when full.

6. Can you post a pic of the car with the lid off of course.

7. Be honest.......when you mess around with your friends or even by yourself do you turn the HS needle in to get more speed to the point it is running it's fastest?? Not assuming anything but gotta ask.

8. Double check around where the carb goes into the motor for any air leaks.