This was guaranteed when two seconds after that, the motor died. I was about 50 feet up and still above landable terrain, so it was a non event to glide into a smooth landing. I checked the gas tank and discovered the problem was that the fuel had been turned off at the tank. Probably by Mike when he repaired the cage. I turned the fuel back on and motored back to the truck.
What I expect happened was that I burned the fuel that was still in the pipeline during the warm up and there was very little left when I began the launch which was exhausted in seconds at full power.
Back at the house I ran the motor for several minutes without a burp, so I should be good to go the next time my schedule and weather permits.
Last week Mike had been kind enough to to weld up the damaged cage and replace the nose wheel.