I will try and post pictures tonight or tomorrow. I don't think there is anything unique about my build, though, so I wouldn't expect any great discoveries.
The intake has plenty of room.
I have sprayed WD40 all around the intake areas and had no changes in RPM. The only leak I've identified is right where the muffler mounts to the motor, there is a slight bit of oil. I replaced the gasket here and it seems to have fixed the problem. Tonight I'll wipe it down so once it stops raining and I can ride it I'll see if there's more oil stains.
The spark plug has a good healthy brown to it. I have not yet taken apart the carburetor, but I am a little green when it comes to that. I'll have to do my research. I saw a video of someone taking apart the carburetor on a china girl and it looked very simple.
Thanks so far guys, I'll keep you updated with pictures and my experiments.