there should be a sheet metal shroud attached to the exhaust manifold, and a pipe from there to the airbox. above where the pipe goes theres a dome looking thing with a vacuum pipe connection to it, whch is hooked to an inlet air temp sensor in the side of the airbox, finally the other vac nippe on the airbox sensor is connected to a nipple round the back of the carb. Check all of the above, and make sure the war air diverter flap opens when the engine is running.
There is also a heater on the front of the carb, make sure this gets 12v with the ngine on, and the heater itself works properly. Make sure the earth lead from carb to rocker cover is present too, so all the electrical devices on the carb can earth properly
