Topic: 1977 cb400f carbs

[jcoryea1]

Hello everyone-
  The outer two carbs on right side have been removed and cleaned with yamaha carb solvent for the third time..changed to iridium plugs..now it's running on four(all pipes hot, although the two outers still  feel less hot. Now the symptoms are ..revs are slow to go down when throttle is closed(scary) and at cruise in any gear ,the revs seem burbly(sp?) not distinct,as four cyls firing cleanly. When the throttle is opened, it readily takes the revs.Float bowls  were inspected ahd no debris seen..I have a fuel filter installed..carbs were rebuilt with available carb kits..stock air filter. .I feel the problem still lies in the outer two carbs(right side sitting on bike..any suggestions? The bike did sit since 1986 to 2010,but was in great shape..tank not rusty.  Also, I'm hearing a tinny sound in lower front of engine(bike has 14K on it, possible timing chain..we tried to adjust the set screw, but wouldn"t budge) Top end sounds fine.Thanks
  John Coryea

[flybox1]

hanging idle sends me to look at carb to head boots to check for an air leak, spray wd40 on and at each end of the boots while the bike is idling high, one at a time, and note a change in rpm. if it changes, there is the leak. fix it  ...and then do a proper vacuum sync of the carbs?

after lostening the camchain locknut and screw, did you press a small screwdriver down onto the cam adjuster to 'hear' it smoothe out (then lock the adjuster into place with the locknut and screw?

[MoMo]

Did you remove the slides, clean and polish them and the carb body?  Did you remove the midrange jet and clean out the orifices?  #3 here   http://www.mrcycles.com/fiche_section_detail.asp?section=121666&category=MOTORCYCLES&make=HONDA&year=1975&fveh=2911    A 400 sitting that long with fuel will need that maintenance,  all 7 I had needed that done. It is a pita but necessary...Larry