View Full Version : Loud backfire

05-17-2013, 05:06 PM
The scenario: I got off the bus in Louisville and the 40 started up just fine with about half choke. I cruised the short distance to the Conoco to fuel up and afterwards when I went to crank it, my starter clicked (normal) so I kept cranking until it fired. When it caught, the loudest backfire I've ever heard occurred, probably nearly killing the elderly couple next to me (she screamed as loud as the backfire and I assume everyone over 50 has a weak heart).

The choke was still half out, the engine was not all the way warm but I probably didn't need any choke at this point.

Did I cause this by having the choke engaged? Should I dig for further cause or ignore it unless it happens again? If my backfire causes so done else to have a heart attack, am I liable?


05-17-2013, 08:54 PM
I'm thinking you running with the choke on might have richened the mixture enough to get some unburnt fuel in your exhaust. Which then ignited unexpectedly. How's your carb setup in general?

05-17-2013, 10:46 PM
That was my initial thought. Start-up quickly after previous start-up and then choke still engaged...

Carb in general seems ok. It was good enough to pass emissions without any monkeying. I can hear a vacuum leak from somewhere near the back of the carb but can't seem to find where. Someday I'll track down all the little vacuum leaks!

05-19-2013, 06:32 PM
you did't happen to coast in and shut the ignition off before you were done moving did you? Somehow a decent amount of fuel got into your exhaust (as mentioned above).

Maybe pumping like crazy to get it to fire?

A random stuck float?

This is a pretty interesting one, be sure and post if it happens again Uncle Buck.

05-19-2013, 09:33 PM
No coasting in, no pumping the pedal...

05-19-2013, 10:55 PM
This is a pretty interesting one, be sure and post if it happens again Uncle Buck.

:lmao: 1 point for quality random movie reference.. well played! :lmao:


05-20-2013, 07:46 AM
Haha, that is a great movie, and I hadn't picked up on the reference. I just thought he didn't know who the OP was.

05-20-2013, 11:26 PM
Glad you guys picked up on it, I kinda threw it in at the last minute. :)