Hi DDJJKK, welcome to Outdoorking. It is best to post a picture of the part when you ask a question like that, otherwise we have to guess. Here is the assembly diagram for the last bits to go into the crankcase:

[Linked Image]

If I were to guess, my guess would be that you are talking about the Governor Arm Shaft. If so, the diagram shows which way it goes on. Please post a picture so we can be sure we're all on the same wavelength though. Also, Mark may make a different, and probably better, guess than I have.

The governor has a pair of weights on the timing gear. As the engine speed increases the weights fly outward due to centrifugal force, and the levers on the weights push a sliding plunger along the shaft. The fork on the governor arm shaft is pushed by the sliding plunger, causing the governor arm shaft to rotate. Outside the crankcase, the far end of the governor arm shaft has the governor arm clamped to it. Thus the governor arm moves when the engine speeds up.

Last edited by grumpy; 15/11/12 05:01 AM. Reason: Add detail