The weight by itself is probably not the issue. As long as the frame is strong enough to hold the motors steady it should be fine.
Center of Gravity
The center of gravity is the 'balance point' in the unit. For a quadcopter this is generally the middle of the unit. You want to make sure most of the weight (battery, flight controller, etc) is centered.
Found that there is a tilt because of the hanging wire connecting to the motors. Will remove the wire and replace with lighter smaller wire connecting battery to motors. Maybe flip over will be gone then. Will also pursue with receiver after that
That sounds like you don't have a flight controller. You won't be able to fly a quadcopter without electronic stabilisation of some sort. The basic configuration is not naturally stable.
An analogy is trying to balance a stick vertically on its end. You need some kind of active control to keep it balanced, and shorter sticks need faster reflexes. Most people ...