backfire while running

Old 11-10-19, 03:17 PM
Thread Starter
Join Date: Nov 2019
Posts: 1
Received 0 Votes on 0 Posts
backfire while running

20 hp briggs n stratton v twin........ ive cleaned carby..... muffler.......changed spark plugs...... even reset timing but still back fires hard n mainly running at high rev any ideas
Old 11-10-19, 03:43 PM
Rough Rooster's Avatar
Join Date: Feb 2014
Location: USA
Posts: 434
Received 7 Votes on 7 Posts
Intake valve too tight?

Old 11-10-19, 04:07 PM
cheese's Avatar
Forum Topic Moderator
Join Date: Jul 2001
Location: USA
Posts: 17,658
Received 56 Votes on 51 Posts
Is it popping through the intake or out the exhaust?
Old 11-10-19, 07:31 PM
Join Date: Apr 2003
Location: Ohio
Posts: 1,981
Received 20 Votes on 18 Posts
I put in 4 new valve guides into a Kohler opposed twin. Developed a hard backfire on start that happened less and less as time went on. I bet if you get it apart you will find a sticky valve, and if you answer the cheese man, you can narrow it down a bit as to which one.

Thread Tools
Search this Thread
Ask a Question
Question Title: