Kohler CV740-0200 Ignition issues

We have a Kohler Engine on a Bush Hog Zero turn mower giving us some real issues. It demonstrated losing fire on one coil when it got hot then losing fire all together. Tracing that tissues we discovered a defective Ignition Box (as well as a Kohler Fix calling to remove it all together with a new set of Kohler coils.) We got it running only to now find we have a faulty issue in the wiring harness (losing power to fuel shutoff.) We repaired that only to run into run into the mower to run fine then it will all of a sudden shutoff for no reasonable explanation. Can anyone offer any suggestion where we need to look next?

check all electrical connections by hand ensuring they are tight & secure, especially ground straps & cables from engine to chassis etc.