Lowlevel...
you might want to check with grandad. He's got one of those, and had some problems with it at first too, but I think he finally got them worked out. Sounds like low speed needle, but who knows! I know my evo .46 was cranky until I got over a gallon of fuel through it, then, like majic, it just started running great! Have you done the pinch test? And the nose high test?

Blow the "suds" out of it on the ground, then take it back to idle. Once idling, pinch the fuel supply line. After a second or two, the idle should increase slightly, then die. If it dies immediately, it's too lean. If it runs forever before dying, it's too rich. Also, with the throttle at full tilt, hold the nose up in the air and see if it leans out--this is more for the high speed needle, but it could be giving you some fits as well. These things aren't any fun at all, until you get them set up right.

Last but not least, have you replaced the glow plug? Sometimes as a new engine is being broke in, the glow plug suffers a little from all of the compression, as well as a few errant shavings/etc. Your plug may have gone south slightly. Worth a shot, anyway! I've seen a lot of "out of tune" engines become all better with a new plug. I once broke in an engine that went through 3 plugs before it was broke in fully. I no longer have that engine--it belongs to my dad. It's a gold top. He hasn't had an ounce of trouble out of it, but I hated it.

Good luck!