81 LTD 550 float bowls

After getting the carbs back on the bike it started up fairly quickly and settled in to i nice idle with a few adjustments. after a couple minutes gas started coming out of the overflow for cylinder #1 at a steady flow.there was also a slow drip on #2.
Pulled the carbs to check the float needles and seat. They looked fairly new, but i ordered 4 rebuild kits anyway. Installed the new parts last night. set float height at 18mm from gasket surface, put carbs in my vice, held level and attached the tank. Held the tank up on prime to fill the bowls. Carb #1 and #2 started leaking from the overflow. #3 and #4 were fine.
Rechecked float height and put the bowls from #1 and #2 on 3 and 4. And the bowls from #3 and #4 on #1 and #2. Refilled bowls and the leaks moved to 3 and 4. What are the odds of having two float bowls with cracked overflow pipes? Any one have any ideas?

It's easy to check. Pull the bowls in question and fill them while not on the carbs. You should be able to tell if the overflow pipes are the cause of the leak. You can use alcohol for the test to reduce the possibility of fire. Ed

There are two orings on the bowl screw valve. I assume you replaced those, if not, you may want to.

You can do Ed's test to confirm it's not the floats or float valve. Unfortunately, if you are in an area with heavy ethanol use, you may have cracked overflow tubes... becoming a much more common thing. Guys with brass floats are really suffereing.

Yup, o-rings were replaced. Both bowls that are leaking have cracked tubes. I used rubbing alcohol to check for leaks, With a flashlight I was able to see the cracks down the side, especially compared to the ones that don't leak.
Any one successfully repair these?

I've done it on a bowl off one of the Keihin CV34 carbs on my 750/4.

I took the bowl to a hobby shop and found a brass tube with an ID just wide enough to fit over the existing brass overflow tube. Cut the new tube to length, slipped it over the existing brass overflow tube and soldered the bottom where it met the pot metal of the bowl. JB Weld will work also - just make sure you let it cure either overnight or 24 hours. Cant remember which - if all else fails read instructions.

I dont know if your bowls/overflows are much different