I am really confused. I would appreciate any feed back or advice. Basically I have done all the free mods, installed Dr. D full exhaust, AIS Removed. I am at sea level, 80-90 degree avg. temp and my 07 450 was previously jetted as follows: MJ: 170 PJ: 48 Needle: JD red 4th position Everything else stock Results: No sputtering, no backfiring on deceleration but i did have an off idle bog in 4th. After much review of the jetting database and research in general i decided to do the following: 1. Changed main jet to 168. this resulted in crisper throttle, exhaust sound. 2. installed GYTR fuel screw set at 1.5 turns out. 3. installed NGK cr9eix iridium spark plug. seems to wake the bike up a little. 4. installed R&D Power Pump with ALJ set at 40. installed stiffer spring on AP linkage and also did O Ring AP linkage mod. Here are my concerns: 1. Bike doesnt run smooth at mid rpm, it kinda sputters. 2. Although not significant, i do have some backfiring on deceleration. 3. When i checked the plug it was kinda black. The plug has been in for a few months and i was adjusting the fuel screw during this time so i had been running at 2 turns out for a period of time that could have caused this. 4. with the bike running at idle, standing still, i adjust the fuel screw all the way in (closed) and the bike continues to run??? I am thinking, if the plug is dark, i am running rich so i dont need to go back to a main jet of 170. I have messed with the ALJ but i really dont feel anything significant so i keep it at the suggested 40 position. Should i go higher on the needle... to the 5th clip position? What about the bike running at idle with the fuel screw closed? do i need to change to a 45 pilot? Please help, i am beginning to go crazy trying to get everything dialed in. Thanx.