the flapper is in the position to heat the intake manifold when the weight is in the uppermost position, (clockwise standing at the front of the engine), the flapper is in the position to bypass the intake when the weight is down, or the counterclockwise orientation standing at the front of the engine. I can determine this because I have the exhaust manifold in my hand looking at it. If I knew how to post pictures I would. But you are just going to have to take my word for it.
