After adjusting the valves on my 1989 454 LTD, I primed the carbs by putting a vacuum test hand pump to the fuel valve. I flooded out the carbs. Now the bike will run on the fuel in the bowls, but as soon as I open the fuel valve it floods out. I took the bowl off on carb and saw nothing wrong. Any body no what I did to my carbureators?

 

Check your float setting. Float setting too high will let the gas free flow w/o the needle contacting the seat (the float contacts the casting instead).

 

Might as well do a through carb cleaning as long as they are off.
I don't know why the float setting would change unless you messed with it.
But you may have a sticky or bad float needle.

 

right. definitely observe float height and needle pin operation.

(that little spring loaded part that rides on the tab on the float)



chances are the pressure knocked something out of spec.. you can gravity bleed those bowls..

i just had that exact problem with a customer's bike and i'm trying to remember exactly what i did.. lol.. then again, i rebuilt the entire thing anyway.. problem disappeared with that..

welcome to KF!!

 

You might have damaged the vacuum diaphragm within the fuel petcock, if this is where you connected vacuum tool. Anytime the petcock vacuum diaphragm is worn or damaged, you will end up with a fuel leak either at the petcock or carbs or both! I had this issue on my KZ1000P and ended up buying a petcock rebuild kit to resolve issue. No more leaks!