Re: 79 CB750K New here

Posted by Hoko on Aug 28, 2013; 2:58am
URL: http://vintage-and-classic-hondas.81.s1.nabble.com/79-CB750K-New-here-tp4044399p4045217.html

Inspect your float valve seats, if they are dirty looking, polish them with a qtip and chrome polish.  I like to use a drill to polish mine. I clean them with the Qtip and polish and buff them with a thin piece of rag over the Qtip.  If they are pitted, I've heard you can lap them with qtip and toothpaste, (never tried it).  Dirty valves will leak and cause fuel levels to go into the overflow tubes.  Also you should install new needles with the same kind you have.  (all brass or brass with rubber tip)  Yes, your floats are adjustable.  you bend the small metal tab that pushes the needle whatever way you need to adjust it.


The setting for your carbs is 15.5mm

That setting on the diagram of 14.5 mm is for my carburetors in a 78F, yours is 15.5.
After having done all that,  the only thing I know of that will consistantly cause carbs to overflow is very small particles of rust or debris in the gas tank and not having inline filters installed in your fuel line.  You may have to pull that tank and clean it really well and flush your entire fuel system.
If you have rust, check this out.  Looks like it works pretty well.  http://www.xs650.com/forum/showthread.php?t=30