For weaker characters, such as Masktchis, Gozarutchis, Robotchis, and Hanatchis, I'd say about 25-30 pounds, just a bit over it's minimum. And for stronger characters, such as Mimitchis, Mametchis and all the other in between, I'd say about 35-40 pounds.
If it's overweight, though, it really doesn't matter. <_<