Greetings. I have a 2000 XR600 that I'm exetremely happy with, except for 1 common problem.. The "Bog" just off idle is a real pain in the ass for me. I ride road and dirt and it really irks me that I can't get the power on smoothly at say, a roundabout or up a steep hill between narrow trees etc. I've read here somewhere that a 2 mm hole drilled in the slide 12 mm from the top of the slide will help get rid of this problem. I'm a printer, not a mechanic, so my understanding of how a carby works is limited at best. Can someone explain in simple terms how this vacuum process works and will a 2mm hole actually help and why?? Does the positioning of the hole around the circumference of the slide matter and why? What does "shim" the needle mean?? Thanx in advance.