I MIGHT have found the culprit!
The cover to the leaf trap has a crack and is not sealing properly.

I removed the check valve on the intake pipe yesterday to see if it was the problem, so I'll have to wait for a buddy to come by and give me a hand before I try again.

I sealed the leak on the cover, but I'll have to wade out into the pond and put my palm over the mouth of the intake pipe while he fills the pipe and leaf trap with water. Will install repaired leaf trap cover and give it a try.

All of this is a WAG.

Before I do all of this.. would a "non-sealing" cover cause the pump not to prime?

Thanks!

Plant Oak Trees!
Catch Tarpon!!