On Aug 30 I had just returned from a little drive. I fiddled with the trunk hinges for a couple minutes, then restarted the Tiger to drive it into the garage. I switched it off seconds later when smoke and heat were coming out of the hood gaps. The paint started to bubble...

With the hood open, a quick squirt with the garden hose, thankfully just a couple steps away, extinguished the flames.

As best I can determine, a little fuel came out the bowl vent (Boiling? Float valve issue?) and ignited when I started it (spark from the solenoid or generator?).

Not much damage except the hood, the bubbling and soot underneath, and the big bubble on the topside are quite evident.

Oh, the trunk hinge I was looking at is broken, so I had problems at both ends that day.

Additional Info: I could find nothing wrong with the carb when tested multiple times later. I did some on line investigation of gasoline boiling points, and found a video where a fellow got one component of the gas to start boiling at 170F! My thermostat is a 190F. The Logical conclusion? The carb is sitting on a big hot hunk of metal that gets no airflow when suddenly shut off...

To test this, I added a clear drain hose to the suspect carb vent, and went for a little drive. The hose was clear when I got back, but a few minutes later there was evidence of fuel in the hose. So it looks like fuel in the bowl can boil enough to force some out the vent. Even after 20 minutes with the hood open the intake manifold was still at 180F according to my IR thermometer.

Later Update: I opened the carb and confirmed that the float level is correct, and there was no dirt in the bowl, so it must all be attributed to the boiling.

See the last frame for my solution.