I use an old fashioned method. Set the high speed needle to max rpm, back off about 1 or 2 clicks. Then I get a buddy to pick up the plane. Holding it level I go to max throttle. Then my buddy tilts the nose of the plane up toward vertical. If the engine sags down, open up the high speed needle a click or two. Repeat. When I get the plane set where it doesn't sag down, I open the high speed needle another click. I work on the basis that engines running a shade rich have a long, long life span. Engines that are run lean don't have nearly as long a life and oftimes if set too lean will sag down and give you deadstick practice on take-off.

Once the high speed needle is set, follow the instructions in the above posts for setting the low speed needle.