First Build - Head Gasket Leaking?

[Miriax]

My head gasket seems to be leaking half-burnt oil. It's thicker than the fuel mixture, but still runny, and very very dark brown.
I've searched around, and I've seen people saying that it's normal, or to mill the head, but this is a brand-new build. I haven't even messed with the carb internals yet, just the idle screw.
The engine also seems to be running air/fuel rich. The smoke the motor makes is very blue, probably from a rich oil/fuel mix, but the engine bogs out almost immediately if I open the choke more than half-way.
I've been running the motor with the choke closed all the way, all the time.
Refer to the picture to see the stuff leaking out of the head gasket.
I'd prefer to avoid taking the carb off to change the internals, because the way I have it mounted, I'd have to take the whole engine off. If that's what I need to do, though, that's what I need to do.
Thanks for all the suggestions and help!
~Miriax

 

[Al.Fisherman]

If you want the head gasket from leaking I'd suggest milling the head and cylinder. You might get by with just the head. I have NEVER seen a head that was flat. On a flat surface (glass best) lay a sheet of sandpaper 230-250 grit. Take the head and sand the gasket surface. Only take enough off ..you can tell by the shiny aluminum. Coat gasket with Copper Kote or aluminum paint. If you are using the acorn head nuts, get rid of them. Most likely a 8mm x 1.25 metal locking nuts will do. I have ran into my last engine that they were 8mm x 1.0

 

[shell shock]

i had the same problem on my first bike. wht A.I suggested is a easy fix

 

[Pepe]

I'm having the Same problem on my bike and when when she starts it makes a very unusual sound like a grinding poping sound anyone please help I'm desperate to ride it again