Maybe some of you who have tried to fix the common KLX 140 bog will read this. My sons KLX 140 had the off idle or 1/8 throttle bog. I tried everything other than replacing stuff in order to fix the bog but nothing worked. Very frustrating. I couldn't figure out if it was running to rich or to lean but I finally came to the conclusion throughout all my testing it was running to rich in the specific fuel curve which was causing the bog and no jetting was going to fix it simply because some carbs are limited in jetting options and adjustability. So in a last ditch effort I changed the spark plug from a 7 to a hotter 6. So far so good. The bog is no longer, and it seems to pull harder too. Problem though is that I believe its now running lean on top so I'm going to try a 105 main.