Fixed it!
Long story. The engine is really 15 hp mounted on a pressure washer and has a recoil starter! About ten years ago, I decided to install a starter. Bought a used starter and flywheel on Ebay and installed them. Then, things get a little foggy. I thought I used it a time or two before putting it away. But evidently not. The parts were for a 16 hp engine, not a 15. The difference is in the ignition timing. The 16 uses electronic spark control and advanced static timing. My engine had the "dumb" ignition, which gives too much spark advance at low speed, hence the kickback.
The solution was to remove the starter ring gear from the 16 hp flywheel and install it on the 15 hp flywheel, it came from the factory ready to accept the gear. Sounds simple was was a ton of work, mostly due to the sheared Woodruff key jamming the flywheel in place. Once all the cursing was done and out of the way, it fired up about the second time over.
