I didn't think of the idle screw as &quot;getting more air&quot; by turning it out. I know the tractor ran rougher the farther out I went. I haven't had time to play with it today, but when I get to it I'll start with one turn on top. I have the &quot;load&quot; at 4. 

Since I intend to give it a tune-up I was looking things over on the &quot;coil side&quot; of the tractor. It has been converted to a  3 wire Delco alternator (3 wires - Battery, Regulator, and field). I found it odd that whomever wired it has the terminal marked &quot;R&quot; or &quot;1&quot; going to the coil. The &quot;F&quot; or &quot;2&quot; is jumpered to the &quot;batt&quot; terminal. I think a rewire will be required. I was thinking of using an early 1550 diagram for a guide.