Hello, welcome to Chief Delphi! Good to see more FTC people on here!
According to
Pitsco, the HiTechnic standard-scale servos have up to 84 oz/in. of torque.
And the
HiTechnic quarter-scale servos have up to 183 oz/in.
You can do the math yourself if you'd like (I'm not very knowledgeable with physics honestly), but my instinct would be to say that the standard-scale servo couldn't do it, especially with the weight out at the end of a four-bar (which would act as a lever against it).
I don't even know that the quarter-scale could do it. It might be able to pull it off if you run it through at worm gear, although it would move more slowly.
Hobby servos aren't generally made for moving loads like that, they're better for gripping claws, latches, and small, low-force applications of that nature.
If you'd like to test it, make a quick prototype. Throw a bar of aluminum about the length of the proposed 4-bar on it, and stick the weight on the end of it. (keep in mind that the servo has to lift the four-bar mechanism along with the weight).
Is this the robot's primary mechanism? Why aren't you able to use the Tetrix DC motors?