I have finished my break in period. After 350 I am ready to set her to number 2. I have the old gas setting system and she is set on #4. I have read the the manual and followed it closely. For some reason I am unable to move the gas adjustment nut. It is extremely tight! I am using a 5/8 wrench. I have tried removing the barrel ( per the instructions on page 16 of the manual) nothing is working. If I place to much persure on the nut it will strip. Am I doing something wrong. Please help!