Uploaded July 2017 | Updated September 2026, 1 day ago
See the full article here: newsline.kitplanes.com/2017/07/05/priming-with-the-pump
If you squirt the fuel with no suction, it will all fall back down through the carb, and collect in the air box. If you then get a backfire, you are likely to have an air box fire – and those can be very bad. By the time you know (in the cockpit) that you have a problem, the fire can really be going!
So how much fuel are we talking about? I happened to have a carburetor I am working with on the bench this week, and it still had fuel in the float bowl. So here’s a little video of just how much gas comes out with each pump. That spray, by the way, went up about six feet into the air (before falling back down as a fine mist all over my head).
See the full article here: newsline.kitplanes.com/2017/07/05/priming-with-the-pump
If you squirt the fuel with no suction, it will all fall back down through the carb, and collect in the air box. If you then get a backfire, you are likely to have an air box fire – and those can be very bad. By the time you know (in the cockpit) that you have a problem, the fire can really be going!
So how much fuel are we talking about? I happened to have a carburetor I am working with on the bench this week, and it still had fuel in the float bowl. So here’s a little video of just how much gas comes out with each pump. That spray, by the way, went up about six feet into the air (before falling back down as a fine mist all over my head).
