All gassers are not heavy,,I am using a ZDZ40 and have all engine components(batt,ignition,switch,fuel dot) mounted on the box,and I had to remove the two elevator servos and and install one hitek MG under the pilot seat with carbon fiber rods to get it to balance without weight added to the nose as mine was gonna take 9.5oz added to the FW to balance it,,I chose to move things instead of adding weight,,I have a 1600MAH batt and receiver as close to the engine ignition as I dare as well(10-12inches), all of this tells me the ZDZ is light