Re: 79 cb750 rattle at low rpms

Posted by Re-run on Jul 29, 2012; 2:20am
URL: http://vintage-and-classic-hondas.81.s1.nabble.com/79-cb750-rattle-at-low-rpms-tp4026044p4026046.html

For the rattle, put in neutral and pull in the clutch. Does the sound diminish? Most likely it will and if it does, the carbs need to be synced. Any time you pull apart the carbs, this would need to be done to even the craw on all 4 carbs.

The popping on decel is most likely caused by 1 or 2 things. The air cutoff valves are not working right, or the idle mix on the carbs needs to be adjusted. An easy way to check is to pull the plugs and see if they are white or black. White plugs mean the mix is too lean, black means it is too rich. They should be about a light tan color.