Weird Carb flood

[M@]

Hi,
76 RD 400.

One carb overflowing.

Replaced:
Needle and seat with viton
Float

Adjusted:
Float

Circumstances:
A year ago I was riding in the yard to the delight of my 2.5 year old and I had forgot to turn the gas on.  Eventually it starved.  I turned the gas on and then it started flooding on the one side.  If I tap that side hard it will stop.  If I ride around it will start flooding again.

I just can't figure out what else it could be.  There's nothing in the bowl that could be rubbing.  I even trimmed the gasket totally flush (this gasket has been in the carb for 10 years without a problem).

Might it be the "filter" thing in the tank has came loose from riding in the yard and now it's letting dirt in?  There's no dirt in the bowl or the seat... I'm totally at a loss to the point of eyeing pwk 28s.  I don't think I really want to go that route just to avoid rejetting....

HELP!?!?!

Matt

[quocle603]

I've had RD carbs that had different types of needle valves to stop the gas from flowing. Not sure if the one you purchased was the same as the original. Either something that is stuck in the valve or your float height is not properly adjusted. Those are my two guesses.

[Hardy]

You could try and test the needle actually shuts the flow fuel off by removing the fuel bowl manually lifting up and down the float (gently)

Have you checked you don't have a hole in a float?

[M@]

I replaced the valve and the float after the problem and it persisted.  I've pulled the carb around 10 times and there's not be anything in there.  It's adjusted per the manual, and when I tap the carb hard it stops. 

[rodneya]

How old are your fuel lines? Some break down over time and loose tiny little bits that are hard to see.

[85RZwade]

Matt, some thoughts:
Sealing washer under float valve seat?
Bench test as suggested above, does valve shut off flow of fuel?
Float and needle moving freely, not binding?
Chuck a Q-tip up in your drill and lightly lap the needle seat
Set fuel height carefully, not float height
You'll get it!

[m in sc]

make sure the float can move freely with the bowl on. take carb off, and drain it. then shake it see if you can hear the float moving. if not, could be the float rubbing something internally. i saw you looked at the gasket, good start.

also, pull the seat out.  make sure the gasket under the seat is good (and there). 

aslo verify the overflow tube isnt cracked

[Hardy]

aslo verify the overflow tube isnt cracked

Good point about the overflow tube! I had one come loose in my bridgestone 350. Took some finding to work it out.