How to set points on a kohler 181 engine?

Turn engine until you see the gap open to its max. Select the 18 thousands feeler gauge (or a business card) and slide it in the gap. It should slide in without moving the points open any more and it should hit both sides of the points. It takes a little practice to get it right. If they need to be adjusted there is one screw you will see with a place to put a screw drive in to make the adjustments. Loosen just the one screw where your points open and leave the other tight unless you can't make the setting move then loosen it just a little so it will hole the setting when you move them. Tighten the screws and check your work, it often moves. It would be best to run a point file or sandpaper through to clean out any corrosion or dirty on the points surfaces first.