This is for an 1979 Honda CBX. I installed new float needles and seats. Also, I adjusted float levels to factory specs. All carbs are still flooding.

Question edited to add maker.

In my experience it is seldom float level unless you bent it during the overhaul. Here is the section from the Service Manual. 8mm or 0.3".

https://www.manualslib.com/manual/817941/Honda-Goldwing-Gl1500.html?page=89

You need a float level tool as mentioned in this excellent video.

https://www.youtube.com/watch?v=sDYUGnso0lA

More here

https://www.google.com/search?q=1994+gl1500se+adjust+carb+float+level

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Float valve seats have o ring seals on some carbs,
check those. Float level must be set correctly
or floats will hit the carb body before needle closes.
Floats must move easily up and down.
Carb body air vent passages must be clear.
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Did you clean the seat,where float needle goes? Use q tip with toothpaste and polish seat then clean and install.

1. remove the hose from the carb and see if the petcock is shutting off the gas and if not clean, repair or replace the petcock.
2. look in the tank and see if it has rust in the tank even a small haze of rust as rust will cause the needle and seat to stick in the carb and make the gas leak. If the gas tank has a lot of rust it may need a tank rubber liner kit added or even a new tank to stop the leaking.
3. if the bike has been sitting for a while it may have trash in the fuel system(carb/petcock/tank). Rust or any trash can cause a leak. Properly clean out the carb and fuel system and add a new filter when done.
4. Improperly adjusted or bad needle/seat or float in the carb will cause continual leaking. Replace the needle/seat/float and adjust the new one when installed. Check your service manual for float adjustments.

your float settings inside your carb are set wrong read my advice to resetting them and you should be ok
You'll need to first start off by removing your carb. Be sure to clean the surrounding area to the best of your ability to avoid dirt and debris falling into your carb; or worse, your engine. After you've removed your carb I would suggest a thorough cleaning using carb cleaner (or equivalent) and compressed air to ensure that all jets and passageways are spotless. Avoid using wire or other tools to clean orifices of jets; it's all too easy to alter their original designed dimensions.

After your carb is clean you can now set your float level. The picture below will allow you to become familiar with the parts that are responsible for maintaining the correct float level in your carb. There are four basic parts, the floats themselves (part of the float assembly), the float assembly tang, the fuel inlet needle valve, and the fuel inlet valve seat.


(Float assembly pivot pin not shown.)


It is always a good idea to remove the float assembly pivot pin (already shown removed) and extract the float assembly and the fuel inlet needle. The fuel inlet needle is a wearable part and over time can deteriorate. A worn fuel inlet needle can contribute to an irregular float level. Most fuel inlet needles consist of an internal spring loaded bumper (which contacts the float assembly tang) and a plastic or Viton (rubber) tip. Inspect the fuel inlet needle tip for wear and/or damage. To give you an idea, Eric Gorr recommends replacing the fuel inlet needle/seat assembly every two years. I've found that the average cost is around $15 for both parts.


(Fuel inlet needle shown with Viton (rubber) tip. The Viton is used to isolate the fuel inlet needle from vibration and to create a better seal against the fuel inlet valve seat.)

Now that you've made sure you aren't going to have any issues from worn parts you can reinstall your needle, float assembly and float assembly pivot pin and continue on to set your float level. The float level measurement is taken from the top of the floats (when the carb is positioned upside down) to the gasket surface of the float bowl as illustrated in the next picture. You can use an open-end wrench (sized per your spec), a small metric ruler, or a float level gauge. The tolerance for your float level is usually around +/- 0.50mm.




When setting the float level be aware that the spring loaded bumper on the fuel inlet needle valve may have a tendency to compress under the weight of the float assembly which will skew your measurement. Before you obtain your measurement you'll need to make sure that the float assembly tang just barely makes contact with the spring-loaded bumper. Sometimes it is easier to hold the carb body at a 45-degree angle to avoid compressing the spring in the fuel inlet needle.




If you find that your measurement does not match your float level spec then you can carefully bend the float assembly tang to achieve your desired measurement. Be sure to recheck your work, and if you feel confident that your float level is spot on then you can reinstall your carb and get back to riding.

Remove the float bowls on the left carbs then clean the carbs with spray carb cleaner. Pay special attention to the float needle. A bit of rust, gasket or other contaminant is preventing the float needle from shutting off the petrol. Please rate my answer.

Either the float level is too high or there is debris in the float needle seat. This causes the carb to overflow while running. The fix is:
- Remove the main fuel line with the fuel selector off of you have one.... or pull the line and plug it off / keep the end above the fuel tank then
- Remove the float bowl from the carb.
- Pull the float pin and remove the float and float needle (INSPECT float needle rubber tip for damage or dirt... any damage replace float needle and seat.)
- Spray carb cleaner into the main fuel supply hose / manfold fitting on the carb. Your removing any debris that night be in the float needle seat area
- Spray carb cleaner in all open fuel jet passages without dis-assembly of the carb.
- Reinstall the float needle and float (Float pin too!)
BRIEFLY reconnect the main fuel line
GENTLY lift the float to level.... (Incoming fuel flow MUST stop) Lower float.. (fuel must flow)
If the fuel flow does not stop with the float level.. you must replace the float needle snd seat. After needle and seat replacement if fuel still does not stop with the float level the tab where the float needle is will have to be bent UP no more than 0.010 at a time and then re-test flor fuel stoppage with float level. Adjust tab as necessary to get the float level correct.
- re-assemble carb
- test... running and static.
Thanks for choosing FixYa,
Kelly

this is an oldie need carb rebuilding new needle seats and check the floats for leaks ( put them in water see if they sink.
do a thorough carb cleaning job on them and you need to check specs for float level setting.

You describe a problem with either the float or the float-needle and seat. If the needle is not seating then the gas flows past it. If the float has a pin-hole leak, then it will fill with gas and sink.
On some bikes you can remove the carb bowl without removing the carbs. If so, slide the hinge pin holding the float to one side and remove. The float will drop straight down. Catch the needle since it is now loose. Unscrew the needle seat with a socket.
Clean all metal parts in carburator cleaner...do not get carb cleaner on any rubber part. Shake the float and listen for gas inside or see if it floats in water.
Test the needle seal in the seat by blowing gently thru seat. Needle must seat completly with very little pressure holding the needle in the seat.
Re-assemble with new bowl gasket if damaged. A carb rebuild kit ($35) might be available for 1973 carb and contains all new parts instead of cleaning. Kit might even contain new float and float adjust guide.
Avoid adjusting float level if re-using the old float. If using new float, temporarily install old and measure distance to carb body. Install new and match this measuremnt. Bend tang to adjust.

Good luck,
Techjoel

Dear Craig,
Presuming that the carb is clean !
It seems that you have either set the float level incorrectly, or allowed the needle to become jammed. The float bowl should a little less than 3/4 full of fuel when the fuel is shut off by the needle and seat.
Check that the needle and seat are working correctly by blowing in the fuel pipe, and then closing the needle by hand. Check that the flow is stopped when the needle is fully raised.
The needle and seat do need to replaced from time to time, but generally last well.
If the needle and seat work, then look at the float level.
Further check to see that the floats are not filling with fuel. If this is the case, then the floats will have to be replaced as most repairs are only temporary.
When the floats are fuel logged the needle will not be raised and fuel flow to the carb will be continuous.