Fuel dripping or leaking from carbs can be caused from only a few things:
- Defective/contaminated float valve
- Improper float height setting
- Leaking float
- Defective/improper seating of brass overflow tube in bowl
- Split/cracked overflow tube
- Float binding on side of float bowl
Defective gaskets are NOT the cause of leaking carbs. When the bike is upright fuel level should be below the gasket.
New float valves from kits have been known to leak.
Rust/dirt in tank can cause poor float valve seating.
Leaking at side of carb (as when on sidestand) can be defective gasket and/or warped float bowl.