The very first Gemini's had a air-bleed carb. But the MK II came out and most had a low speed mixture screw in the center of the throttle arm. If yours has no screw in the center of the throttle arm, it is most likely the early air bleed carb. The pictures of the engine in the manual are of the air bleed engine.

If you have raw fuel comming out a exhaust pipe, that cylinder is rither very rich or is not running.

You need to be comparing both pipes.

If a cylinder goes out, you can relight it by putting the glow starter back on that cylinder.