Topic: CB400F Float height problem

[Gentlemanjim]

I rebuilt the carbs on my 1976 CB400F and set the floats at 22mm as stated in the manual,  Problem is that they drain from the overflow tubes.  I raised them to 23mm, but they still overflow if I tilt the carbs the slightest bit.  Should I increase the float height more and by how much?

[Bodi]

Something is not right, there shouldn't be any dribbling with stock float height. Find what is really going on rather than making changes based on guesses. Confirm the floats are the right way up (sounds unlikely, but they "look wrong" when correct), that you are measuring the float height correctly, and that the float height measurement is with the tang just touching the valve.
With the correct fuel level you can tilt the carbs quite a bit without spillage.

[MoMo]

Are all 4 leaking?  If only one or two check the stand pipes and make sure they are not cracked...Larry

[flybox1]

I rebuilt the carbs on my 1976 CB400F and set the floats at 22mm as stated in the manual,  Problem is that they drain from the overflow tubes.  I raised them to 23mm, but they still overflow if I tilt the carbs the slightest bit.  Should I increase the float height more and by how much?

if in your rebuild kit you used new float needles, its possible the internal post height could be slightly shorter, or the spring tension inside is different the the originals.
because of these variables, you have to think of the factory float height as just a starting place, and resort to using the 'clear tube' test to set your float height.
keep in mind...fuel level is the goal. 3-4mm below the top edge of the bowl is sufficient
float height and float valve function get you to the goal.  adjust them as needed to get the correct fuel level.

not for our bikes, but a good example

[grcamna2]

flybox1,that last post of yours has very clear diagrams,thanks

[flybox1]

NP.  We have 2 variations of our carb drains. 
When we remove the drain screw, fuel either flows out of the overflow pipe (like my PD carbs), or, in the case of the OP's 400F, fuel drains out the bowl drain screw hole itself.
For the 400F bowls, the clear tube can either be heated/stretched/tapered, and screwed right into the drain screw hole, or a spare drain screw can be center-drilled and altered so the clear tube can be affixed, and then screwed in place.