I'm working on my 1947 (1st series) COE and I went to start it yesterday. I know you're not supposed to pump the carb to start it, but I may have moved the throttle a little bit. When I tried to start it, it popped once and didn't start. On the second try it started, then sputtered and backfired. This ignited the excess gas in the carb elbow and she started burning. I don't have the air filter or intake runner on it. After a few attempts at blowing it out, I got the fire extinguisher and put it out.
My question is this, did I do something wrong? Would it have caught fire with the full air system in place? Did moving the throttle just slightly the cause?
I don't think it was running out like a stuck float or dirty shutoff. Today I removed the carb and cleaned it all up. I didn't see any problems with the float and valve. I even tested the float with the top of the carb off while sitting on the bench.
I don't want to fear the beast.