Fouling plugs?

[TavisB]

I just fouled a brand new plug (well, maybe 4 hours on it) on my 03 EC250. This is the second time this has happened. I had just started it (first kick too) and was warming it up. It sounded fine then I think under slight throttle (I was revving it just a bit) it just died and wouldn't restart. Put in a new plug and fired right back up and ran fine.

Here's the plug after I pulled it:



When I started it I left it on full choke for about 10 seconds and then 1/2 choke for another 5 seconds or so. Then I took the choke off and just gave it a few revs here and there to keep it from dying. I didn't rev it high (maybe I should?).

Pilot jet is a 38 and main is a 172. Slide and needle are stock. It takes a while to warm up and if I had to guess I'd say it may be running a bit rich.

This is my first 2T in quite a while, and I've never had to mess with the jetting on one (but I have on my DRZ so at least understand the basics).

So...where do I start? Is this a jetting issue, or my noobishness?