This is what I've done it (I'm using a 16% fuel).

4 Tanks fourstroking on the starter box at full throttle, body installed, just to get a little more heat that expanded the sleeve.

6 - 10 tanks on very fat carburation, almost unable to shift into second gear, watching the temperatures. Let it rest for 5 minutes on each tank just to cool it of with the piston on the BDC. Temps should be between 90 and 105ºC.

After this I've started to lean it in small increments, watched the temperature each time. The temp where mine unit performs at it's best is around 125 - 130ºC each unit could be different, but your's will be around that temp. Seen others that go up to 145ºC without a problem.

The break-in will be finished when you notice that idle sounds 'different' and more stable (you will hear it and you will know it is finished). Heard by there that for break-in that engines almost a gallon will be used (it's true - I've used almost 3.5 litres for that small s*cker).