da qui:
http://www.helifreak.com/showthread.php?t=345959
Timing: this direct From the YGE manual but i missed it the first few times.
Inrunner 0 to 12°
Outrunner 18 to 30°
For instance if you come from a castle or you look at the Scorpion spec sheet you will see timing of 5 degrees or low. therefore many people select 6...instead a value of 18 should be chosen since it is considered low for Outrunners on the YGE.
I found that on all my Scorpions and Xera's setting the timing to 18 has worked perfect. I have experimented with 24 and 30 as well and usually the motor will run slightly warmer but slightly stronger. On my 4020-910 Special editions, i have run them at 24 and 30 when using smaller pinions (lower HS) and 18 with bigger pinions. The same is true with my Xera's on 6s. On 12S, the power is more than enough but have found similar results with increasing the timing to 24 and 30. Whenever i have tried running a scorpion/Xera at 0 through 12 i would have poor results and increased motor temps. This can even be more complicated if your PWM value is not correct. For instance with my Xera 560... following Xera's FAQ i set PWM to 12 and timing to 6. My power on 12S was still very good but motor would be at 150 degrees after a mild 5min flight... Changing the PWM to 10 and timing to 18 saw my motor temp drop to 118 F for the same 5 min flight and increase in performance feel. Even my YGE90HV dropped in temp by 10degrees but it wasn't really warm to start so it was less of a concern. I found that even after increasing my timing to 24 or 30 with the same Xera sill ran in the 120's once the PWM was changed.
Also after making any ESC prog changes with Prog card or not, Always be sure to restart the ESC and double checking your PWM and timing values using the Prog Card to ensure they did not get re-set. This can easily happen to anyone!