Flooding carb..

[Athame57]

One of my carbs has been flooding, ie the overflow leaking. This I can stop by tapping the thing with a spanner a while, but what should I really be doing? 

[McCabe-Thiele (Ted)]

I find rocking the bike from side to side off the stand works just as well as tapping the float bowl.

If the bike is used regularly it could be some dirt in the float valve or sticking of the float mechanism. If the bike is only used occasionally then might be old fuel or fuel residue gumming things up in the fuel bowl due to evaporation.

[DomP]

Or is the float set to high?

[Athame57]

Or is the float set to high?

I think I'll go back and check, it is only recently I overhauled the carbs and fitted viton rings.

[TrickyMicky]

I had this problem after the bike had been stood unused for a few years. After a couple of knuckle skinning episodes of removing/replacing carbs I finally stumbled upon the most simple (obvious?) cause, the floats were not moving very freely on the little brass spindles which had accumulated a nice coating of gunge!.  Remove spindles, 30 minutes careful polishing with ultra fine emery, replace carbs and no leaks. Sit back feeling rather pleased whilst opening yet another packet of Elastoplast.  I have owned my 400 for nearly 36 years now, and it's still my favourite one to ride,BUT, when it was designed I think Mr. Honda must have had an evil glint in his eyes, and assembled the carbs, rubber bits, and airbox, hung them on a bit of string and then built a motorcycle round them. Good fun though, eh?  Stay safe. Mike.