I think maybe I found the problem. There is a large spring at the bottom under carb but it looks like carb or intake needs to come off.
If anyone has any knowledge of this please chime in.
Not a fuel problem it runs fine at full throttle and blades engaged.You view is a lot better that ours.
You said...
"There is a large spring at the bottom under carb"
Does that mean a spring came off and is laying below the carburetor?
You took the bowl off and there was a spring in the bowl?
Something else?
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Surging is caused by a fuel problem....engine runs short on fuel...so it cuts back...fuel supply catches up and engine surges.
Symptom of a dirty carb jet.
Not a fuel problem it runs fine at full throttle and blades engaged.
You came here for help because you did not understand what was happening and you were correctly instructed.
It is a fuel problem.
your carburettor has a high speed circuit and a low speed circuit.
The high speed is fine the low speed is blocked.
The carb needs to be cleaned properly.
That means taking it off the engine and removing some welch plugs ( depending upon the actual carb fitted )
you will find detailed photo instructions here http://outdoorpowerinfo.com/repairs/
Bfore you stat take some photos of the linkages, at each end so you can get it back on the machine properly.