Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!linus!genrad!decvax!harpo!floyd!garry
From: garry@floyd.UUCP
Newsgroups: net.auto
Subject: engine backfiring
Message-ID: <1695@floyd.UUCP>
Date: Tue, 28-Jun-83 15:38:22 EDT
Article-I.D.: floyd.1695
Posted: Tue Jun 28 15:38:22 1983
Date-Received: Tue, 28-Jun-83 22:21:31 EDT
Lines: 10

backfiring under deceleration is often a symptom of innacurate
ignition timing.  if the timing is too far retarded it will cause
this.  what happens ( i think ) is that the spark fires too late
to burn all the fuel/air mixture before the exhaust valve opens,
so some of the combustion is taking place in the exhaust pipes.
i had this problem with a 1970 bmw 750 motorcycle, and a good tune
up, including setting the timing, fixed it right up...
			garry hodgson
			BTL whippany
			floyd!garry