Yeah funny enough, the BEC output on the MM1 is only 5.5V. On my own CC BEC I have set the output to 6.6V, that way I get the maximum performance from my servo, which is designed to run on 6.6V.

As Jerm13 says, change that Savox servo in a hurry. There's so many other good ones out there. You could look into the HiTec, Sanwa, Multiplex, Futaba or some other good brand, I know many LOVE the Savox brand, because they are relatively cheap and has good specs. But I feel they make far too much noise and I hate when servos "sings". My own favorite is the Xpert servo brand. I plan to change all the standard sized servos in my cars to Xperts over time. Yep I may be a bit biased.

They are brushless, so they are very energy effecient and should last for a long time. Plus they are fast and have lots of torque, even their low voltage range (4.8V - 6.6V) An example is the Xpert WR-4401 I use my self it has these specs.
Speed:
@4.8V: .106 sec/60
@6.0V: .085 sec/60
@6.6V: .077 sec/60
Torque:
@4.8V: 14.72 kg-cm (204.31 oz-in)
@6.0V: 18.40 kg-cm (255.39 oz-in)
@6.6V: 20.24 kg-cm (280.93 oz-in)

If you want a look at the Xpert range, here's a couple of links.
http://www.amain.com/search?cID=1&s=Xpert

http://www.xpert-rc-us.com/category-s/1837.htm