stuttering under throttle

[gdrudd13]

I have a problem, again, with my bike. It seems to be stuttering when you give it throttle. I don't know how the diaphragm works, but you can see it moves in a way that matches the stuttering. If that even makes sense. It will idle fine, but when it's just sitting, twisting the throttle makes it stutter and often, the motor will die. I just had it in the shop to have the valves adjusted and the carb cleaned, but rode the bike home. It has been started and left to idle a couple days since then (this was in January). Any ideas what the issue is? If it matters, there is also a vent of somekind blowing air into the intake. I don't remember it doing that before. This is also a California bike that ended up in Kansas/Oklahoma.

Thanks!