Been a while since I saw one of those but if I remember correctly it is supposed to be open about 1/8 of an inch or so when cold. A good way to check if it is at the proper setting is to run the engine till it has warmed up and check the position of the plate. If it is fully open then it is set properly. If it is not open enough, or to much, adjust the linkage so that it is straight up and down when the engine is at temperature. When it cools down, it should be where it is supposed to be. My 2 cents.