I have posted this on the jetting section, I have done countless searches and I am more confussed than ever. I have a 07 YZ450F with Dr.D exhaust and the JD jet kit and I am having lots of problems. I started off with JD recommendations 170M 48P blue needle 4th clip from top and 1 1/4 turns on fuel screw. That was bad, The bike was very hard to start and ran very rough. Then JD told me to go to 45P 170M red Needle 5th clip from top and 1 1/4 turns. The bike starts better but while riding and holding throttle at 1/8 to 1/4 no matter what gear the bike sputters and on decel it back fires like a bitch. My conditions are as follows. 70°F 1200' 93 octane. I want to go back to stock jetting parts, Where should I be on the jetting? Thanks in advance for your help!