Q.Sago palms
We had a pretty hard winter in 2017 in zone nine where I live. The palms on my sago all turned yellow so I cut them off in the spring. My sago is a male and has grown a huge cone but no leaves. Should I break the cone off to encourage the leaves to put out? Or what’s wrong with my plan?

Yes, I would remove the flower. Your Sago has likely spent it's energy making the flower and growing it and removal should help it send it's energy back to the plant.
https://www.gardeningknowhow.com/ornamental/trees/sago-palm/sago-palm-flower-removal.htm