Bogging Issue, Need Help

I just recently (couple months ago) bought a 1980 Kawasaki KZ440 D. It was running great and I had it out on the road. Last weekend I took it out for a long ride. I noticed after a while of riding some fuel was leaking from the the left overflow tube. I am new to bikes but i figured I could fix it myself. I pulled the carburettor and cleaned though it seemed mostly clean. I pulled the float bowls apart and checked for dirt but they also seemed relatively clean. Both float needles seemed to be functioning great. I am told that sometimes the float needles can just become stuck so pulling it apart was probably all it needed. I did ever so slightly bend the tang on the left float so it would close a tad earlier just in case. I have now got everything back together and it is idling fine and not leaking fuel...However...now it is bogging badly when i give it throttle in gear. It seems as though one cylinder is cutting in and out and the tip of my left spark plug is instantly covered in black soot. Did I mess something up? Is there an air leak??(though the boots seem fine) Any suggestions from anyone who has encountered this would be greatly appreciated.

MikeHoncho wrote:

I just recently (couple months ago) bought a 1980 Kawasaki KZ440 D. It was running great and I had it out on the road. Last weekend I took it out for a long ride. I noticed after a while of riding some fuel was leaking from the the left overflow tube. I am new to bikes but i figured I could fix it myself. I pulled the carburettor and cleaned though it seemed mostly clean. I pulled the float bowls apart and checked for dirt but they also seemed relatively clean. Both float needles seemed to be functioning great. I am told that sometimes the float needles can just become stuck so pulling it apart was probably all it needed. I did ever so slightly bend the tang on the left float so it would close a tad earlier just in case. I have now got everything back together and it is idling fine and not leaking fuel...However...now it is bogging badly when i give it throttle in gear. It seems as though one cylinder is cutting in and out and the tip of my left spark plug is instantly covered in black soot. Did I mess something up? Is there an air leak??(though the boots seem fine) Any suggestions from anyone who has encountered this would be greatly appreciated.

What you did lowered the fuel level in that bowl. FYI: the definitive test for having the fuel level too low is to put it in second or third gear at lower RPM with light throttle opening and then open the throttle wide instantly. If it pulls strong, the fuel level is right. If it stumbles or loses power, it's probably too low.

You need to set the fuel levels using the clear tube method.