Any idea why a carb would like to catch fire?
It doesn't back fire and runs great.
Rather often on a cold start the car will not want to start and then suddenly the carb will be on fire.

I would fully understand if there was a back fire, but there isn't.

Seems to not catch on fire if the air cleaner is on it.
I just casually get out and blow on the flames. They go out pretty easy.

 

Valve lash being out of adjustment/mis-adjusted is the first thing that comes to mind.

 

Yep, valve lash or timing. A too rich initial startup combined with one of those will do the deed. Lost my snorkel hood back when I was racing my '71 that way. It ran great, but every once in awhile it would catch fire when started cold, and one time it did it, and I didn't notice until the scoop was bubbling paint on top!

 

hmm, to tight or to loose on the valves?
I guess to loose might not let the valve close tight enough.
I retarded the timing about 2 degrees, but will check the valves.

 

Too tight....intake valve closes later (or not completely if set too tightly)....blows fire back out the intake.

 

if it only does this cold I would lean to a valve that is not seated properly. Once hot things expand and make the seal better. a cold engine compression test, or a cylinder leak down while the engine is cold will help determine this.

Massey

 

Havent done a pressure test... yet...

The car only cranks when it is cold. When it is hot it starts right up.
Anyway, I re-adjusted the valves. This time with the motor running.
2 of them were to tight.