Topic: 78 CB750 k carb question

[nwest4]

Just got a 78 CB750K that has issues, will not hardly run with choke off, have to leave choke fully engaged to run and then its running about 3500 rpm.  As soon as you start closing the choke, it dies.  I have checked the carbs by taking apart and blowing through the passages with air and resetting the float levels.  Also have adjusted the valves and set the point gap but ran out of time before I could check static timing.  One question I have is there is another hose port on the no. 2 carb directly adjacent to the main fuel inlet line?  There is nothing attached to it and I was wondering if this is part of my problem?  Dont see any obvious attaching points for the mystery line in question.  Any thoughts would be appreciated.  Thanx.
 

[eurban]

The hose you are referring to is a vent and is typically just tucked out of the way.  Probably not your problem.  You description sounds like plugged idle jets.  The 77/78 carbs have pressed in idle jets that can actually be removed and properly cleaned.  Wrap a piece of rubber or leather around the idle jet and gently twist and pull.  Once out you can soak them in carb cleaner and then clear with a strand of copper wire.  Simply shooting carb cleaner through the idle jets while installed will not typcially clear them.  This subject comes up alot so you might want to do some searching (under pressed in idle jets for example) . . . . . .