Re: back firing out of #3&4 muffler

Posted by LukeM on May 02, 2012; 12:25pm
URL: http://vintage-and-classic-hondas.81.s1.nabble.com/back-firing-out-of-3-4-muffler-tp3953824p3954957.html

One more thing to check is the exhaust pipe connection.  There should be some copper or aluminum gasket rings between the pipe and the head.  Also make sure the mounting bolts are tight.

That being said, I'd still look at an intake leak or mixture adjustment. Pull the carbs and double check the insides for cleanliness. Set the mixture screws according to the manual, and adjust from there. Might be a carb sync issue, so I'd look into that towards the end of your diagnosis.

Luke M