01 yz250 jetting questions?

[upnorthbacon]

I put 75 miles on my new yz250 the other day. It was running a little rich and I have a couple questions. I'm around 700ft temps around 60-75. I'm running a rad valve which apparently leans it out (according to thier specs), stock pipe, pro circuit sparky. I'm running 172 main, stock needle at 3rd clip, 48 pilot, messed with the air screw and I think I need a leaner pilot yet. When it's cold I need to warm it up for a few minutes before cracking the throttle past 1/4 throttle or it fouls the plug and dies. I've had this happen twice and now I've been letting it warm up for a few minutes before even trying to ride around on it. Do you think my needle is still a little rich and this is why that's happening? I'm thinking at 1/4 throttle the needle is kicking in too rich and flooding it out? I changed it to the 4th clip today but haven't ridden it yet.
We rode a mix from 1-2nd gear single tracks, to 3/4 throttle 5th gear fire roads. My plugs were pretty black, even down at the base inside the threads. I doubt I ran wide open more than a few seconds at a time, I was mostly 1/4 to 3/4 throttle. It ran great once it was warm, no complaints at all, started first kick, ran strong throughout. I guess I'm just wondering if I should leave it alone and warm it up longer, and not worry about it. Or should I rejet the pilot and needle a little leaner? I'm not worried about the main, it was running strong and I'd rather be a little rich on top anyway. Also I was getting around 25mpg which I thought seemed pretty good.