I'm curious where you're able to find a rebuild kit. I've searched fruitlessly.
I cleaned mine recently by completely disassembling and cleaning all jets and passages but didn't have to replace anything. It was maybe a little dirty but not bad. The biggest issue found was that the choke was very hard to operate. I worked it loose and now cold starting is much easier.
I still get some surging so am thinking it's not getting enough fuel as bruceatlam mentioned or possibly a worn out ignition coil.
I can't say for sure if the surging is forever gone, I mowed a hundred yards and my son came by to finish up. He texted me later that the deck "caught fire". Seems it chose just then to freeze an idler bearing. Since then been rebuilding the mower deck. Outside. Between rain storms.
For the rebuild kit, Dealer. Need the number etched into the carb body. Still 90 bucks seems a bit steep to me. But, the barrel awaits us all, I guess.