Carb flooding intermittently

[florence]

Had a horrid ride yesterday in pouring rain, my waterproofs were not up to the job and I got soaked.  To add to the gloom and ironically given the pervasive road flooding, no.1 carb was flooding also.  I had taken apart last weekend and thought I had solved the problem.  There is negligible debris in the tank and I have inline filters.  This has become quite a frequent occurrence recently and I don’t know why it’s happening when for many years has been fine.  The floats do not have fuel in them and the brass vent tube is not split.

Do the float valves wear out?  Is it possible to get decent replacements?

[Athame57]

The last time I had this problem I gave the offending float bowl a knock with a spanner.

[K2-K6]

It can be quite beneficial to polish the bore/seat of the float valve entry.

Something like the wood skewers used in food prep,  set in a drill chuck to polish and clean valve seat with fine abrasive in the order of T-cut etc.

I cleaned one, that had been damaged by owner scratching around in there with a screwdriver, by using fine grinding paste. The soft wood skewer taking on original seat angle to gently clean it of marks.

[Reborn 400]

I've successfully used very fine steel wool on a cut down cocktail stick to polish/clean the brass seat and same on the needle tip. If you look very closely at the tip (use a magnifying glass) you may well see a ridge of hard dirt formed near the tip where the valve seats. It only takes the smallest amount of build up or fine particles of rust in the fuel to get jammed in there and make not seal effectively anymore.
Hope you get it sorted, I know it's really annoying!
New ones can be had but for a ridiculous price.
Don't be tempted by the cheap aftermarket ones available, they are a poor fit and of dubious quality. Original Keihin is best

[Bryanj]

I have seen float needles with a step but alsp floats hanging uo on the pivots