Disc mower cut

I have a NH h6830 trailer disc mower and I have always had a little issue with build up of mudd on the cutter bar. Well now i am trying to mow a field that has 1.5 foot tall ant hills and its kind of wet still. I have raised my spring tension so my head takes 75lbs of force to lift it. What else can i do? Its a rough as hell field with heavy clay soil. Can i lower the amount of force it takes to lift the head?
Do deere disc mowers not plug with mid as bad? Neighbor cut some of a neighboring field that has about the same conditions and his cut way better.

Disc mower cut