RE: Just ordered a MoJo .60
Mine is built with a YS110, HS-965MG's and mostly CA with the epoxy used for the mount and tube lightened with micro-balloons.
6lbs even (dry) when built. After a few repairs I'm up about 3oz's.
There is some variability in the balsa from kit to kit. It actually flies good (and some prefer) up to 7lbs.
I wouldn't sweat it.