lawnboy surging

[MSU car guy]

hopefully this is an easy fix that someone can help me with because im at a loss. i have worked very little lawnboy push mowers. one would think there easy to work on. im working on 3 lawnboy mowers with the same surging problem. one is 1 yr old used very little. the other 2 are 2 or 3 yrs old. the newer one i replaced the complete carb assy after i went thru it 2 times. no change still surges. one other thing all 3 blow/leak fuel from the muffler. i could really use the help. thanks

[Bill Kapaun]

http://www.lawnsite.com/showthread.p...awnboy+surging