When you back off the throttle suddenly, the movement of the exhaust in the
exhaust system will continue to move, it also has a lot of unburned or
partially burned fuel, and it wants to suck in air from someplace. So any
air it gets from outside the exhaust system will be rich in oxygen, just
what it needs for an uncontrolled burn. Read that as loud bang!
Others are partially right that you might have a too rich fuel mixture, but
without the oxygen rich air being added to a hot pipe system, it just passes
out the tailpipe as pollution.
Later, Pa
> But Paul: Why would an air leak in the exhaust cause an afterfire??
>
> Geoff Branch
> ----- Original Message -----
> From: "Paul Asgeirsson" <pasgeirsson@worldnet.att.net>
> To: <SDOliner@aol.com>; <gjbranch@comcast.net>; <spridgets@autox.team.net>
> Sent: Tuesday, July 27, 2004 10:47 AM
> Subject: Re: back firing on acceleration
>
>
> > I'd be suspicious of an air leak somewhere in the exhaust system. Try
the
> > flange, pinhole somewhere in the muffler connection, anywhere between
the
> > muffler and engine.
> >
> > Paul a
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