I have a 18 27 row crop that I rescued after being abandoned in the field in 1941 or 1942.  I have been going thru the engine and installed the governor and magneto when I realized the governor had an impulse device which I am sure means it must be timed with the camshaft gear.  There are no markings on the governor gear that I can find for timing.  Can anyone tell me how to time it.  Also I noticed the shaft on the governor has space and keyways for two gears. The gear that meshes with the camshaft gear is within the front cover.  The second space( and keyway) on the shaft would be outside the engine front  cover under a separate cover that covers the nut on the end of the shaft.  Is there something missing or is there nothing in this second position?