You will need to service the carb. I do these right on the machine. Pull the air filter assy, clean off the outside of the carb body- then remove the 4 screws that hold the top of the carb and then the top. You can remove the drain and clean everything out w/ carb spray cleaning all the passages in the top and bottom. The spray will shoot back at you at times so be cautious and wear goggles. You will have to replace the body gasket only if it tears. Remove the fuel filter , flushing fresh fuel through the lines completely and then replace the filter. That ensures all fuel is fresh going into your freshly cleaned carb...

In addition to tomplums great advice I would also remove the gas tank and clean it out if you machine is a few years old. You maybe susprised whats laying at the bottom where the fuel pick up is. And if this machine is over 7 years old I would personnal change the fuel lines. That way I will not have to worry about a fuel contamination problem for quite awhile unless something unusual happens like fueling it with contaminated gas or letting it set for a long period of time with todays gas in it.

Still fuel starvation sounds like. When you had the top off the carb, did you probe the brass looking orifice looking up at you in the top of the carb body. Use "tag" wire of something similar.

Also check vacuum line running from the engine block to the bottom of the fuel pump on carb. for leaks. Fuel pump its self may not be working properly.

Walt Conner

Forgot to add, IF you don't find anything, might try Seafoam in the fuel per instructions on the can.

Walt Conner

I also noticed that when I put the mower in gear and it starts moving the surging stops. Anyone know why this happens.
Thanks

There is small brass tube. Its end is cut of at an angle and the tube is tilted upwards but the opening is pointing downwards. Is the the brass looking orifice that i am supposed to probe with a wire?
Thanks

Hey, I am having the same surging. After reading the post for carb rebuild, I am now more familiar with why this is occuring. See optional link.

Here is a link that might be useful: Need carb rebuild kit for JD L111

I opened the carb again and soaked it in hot water and dish washing detergent. Then cleaned all the jets and ports with compressed air. When I put it back and started the engine there was no surging. Got it fixed.
Thanks to everyone.

I have the same problem with mine and it has a new carb and newish fuel pump any ideas on how to fix?

Just moved the right hand spark plug wire away from all the pipes. Runs like it's brand new!! :)