You have a few things to do:
1. Make sure that you have fresh fuel.
2. Replace the fuel filter in tank.
3. Replace spark plug & check for spark.
4. Clean air filter.
5. Remove muffler and check for scoring in cylinder.
Try this first and let me know if it corrects you problem. If not I will give you more things to check.
The low speed screw usually has a spring.
Regards,
Outdoorking
[This message has been edited by Bruce (edited 16 October 2002).
[This message has been edited by Bruce (edited 06 November 2002).]