I have done several and i do it somewhat different. Fill up both tanks to the cap. Take off on the left tank and climb to 3000 ft, set 2500rpms, switch tanks and hack a stop watch. Fly for one hour then switch tanks and go land and fill up the tanks again. Note the gallons required to fill the right tank. Then take off and climb back to 3000ft, set 2500 rpms and see what the fuel flow indication shows. Go into the setup menu and change the k-factor until the displayed fuel flow indicates the same amount that was required to fill the tank. It usually takes 1000-2000 k factor to get it perfect. You now know exactly how much fuel the engine burns at 2500rpm and 3000ft and now have the displayed fuel flow reading to match. It will be within .1 gals/hr when done and does not take multple fuel loads and note taking to figure out the perfect k factor for you installation.