Hello and thanks to anyone who takes the time to read / respond.
I'm looking for some advice concerning a suspected leaky float valve needle seat.
Short story: Bike was sitting for years. I took the carbs completely apart and replaced everything that came in the carb rebuild kits I ordered. #3 carb only is leaking bad. The needle valve seats seem to be pressed-in and I think I might have ruined it while cleaning. Can't find replacements anywhere. In the event that I need to replace one, what do I do?
Possible solutions found on this forum to try first:-Test bowls for leaks (overflow tubes could be cracked or not sealing properly, common issue apparently)
-Try lapping the seat using valve lapping compound and a spare valve needle then bench testing to prove good seal
-Double check float level using clear hose on all carbs (I don't suspect float level is the issue since the other 3 carbs are fine and all the floats were set to 14mm)
Adjust float level to 12mm if needed (I hope I don't have this upside down)
The long story:
The #3 carburetor on my PD46 set is leaking from the overflow hose. A lot - not a little dribble.
I have disassembled, thoroughly cleaned and re-assembled with rebuild kits (parts replaced: main jets and emulsion tubes, slow jets, float valve needles, floats, throttle needles and seats, air/fuel mixture screws +o-rings and washers, bowl gaskets and top cover gaskets from vintagecb750.com)
Floats were set to 14mm.
While cleaning, one of the carbs (I BELIEVE it was #3, will confirm tomorrow) had a particularly crusty seat. I made a contraption using a pipe cleaner to try and clean it out but didn't notice it had a sharp metal end to it... Worried I ruined the seat. It looked a bit chewed up.
I'd like to try lapping it but I'm thinking WHAT IF there's not enough material left for the needle valve to reach up and make contact with. Time to look on evilbay for another carb?
