In Reply to: Re: Back Fire posted by Bruce (VA) on November 19, 2017 at 08:40:14:
A short in wiring can also cause backfiring I found out years ago. I was mowing grass after work one Friday evening and it was getting dark. I wanted to finish up as I was going away for the weekend. When I pulled the light switch on, the engine would start backfiring. I shut switch off and it stopped, pulled switch on and it would do it again. The next weekend I got into the lighting system and discovered that one headlight had a hot wire worn thru to bare strands and was shorting out intermittently.