Carburetor flooding

Original (recently rebuilt) carburetor on a 87 SN is flooding from both secondary boosters when engine is running. The engine runs poorly while this is occurring. Is this caused by a stuck needle valve or maybe a clogged passageway? Removing carburetor to investigate and to refresh rear bowl and needle valve. Any other tips or suggestions? Thx

Hi KENO,
It just started flooding. The boat was just put in the water two weeks ago after a partial restoration and was running good (just under 10 hrs). I hope I find some junk in the bowl/needle (just pulled into the parts store for some carb cleaner). I’ve adjusted floats with center needles and bowl sight plugs but never this type, any tips? I do have an old Holley book to reference...
Thanks for the reply, I’ll repost with findings and test run results.

Make sure you remove the float so you can pull the needle out of the seat assembly, then remove the seat assembly and blow out the bowl inlet passages with air,

Float adjustment on this style is a small tab that rides against the needle. You bend the tab

Your old Holley book should cover that but being the rear bowl I don't think you'll have to adjust it, especially since you had 10 good running hours. It didn't magically get bent out of adjustment

Another kinda really slim possibility would be the float having a hole in it and filling up with gas

Debris clogging the needle/seat.....It's happened to many of us. I had it happen on an almost new QuickFuel M-600 carb. Replaced needle/seat with free-bee from Q.F. Good to go for many more hours.

Glad you found and fixed your problem quickly. Happy boating.

JQ