Ladyfriend of mine was given a 5 year old Troybilt riding mower w/B&S 13.5? HP engine last year. I think her other friend simply buys a new one every 4-5 years and does nothing to them in between.
Anyhow, after new blades, air filter and prefilter, and it's first oil change, it ran fine a few times. Then she got a crankcase full of gas. Common with these gravity fed Nikki carbs which are similar to the OP's, though a different model.
A kit did not fix that problem and I can't see why. Read that is a common occurrence so I got a new ChiCom knockoff. It fits well an looks identical at a glance, but side by side with the old one, there are some small differences which indicate a different manufacturer.
New carb doesn't leak, but it wouldn't idle properly: severe surging. Adjusting idle mixture screw did nothing. Checked for vacuum leaks and seemed to find one, but torquing the mounting nuts didn't make much difference though spraying carb cleaner indicated no more leak.
Finally took a piece of wire and checked the passages. The ones for the idle circuit? from the air intake side and fuel (bowl) side were not drilled through. Bushings seemed okay though. I might have drilled the fuel side, but I can't drill the intake side.
I had selected a seller whose ad stated for factory defect: lifetime warranty. Took an extra message to convince them this carb is bad. They finally told me to order and pay for another one, then they will reverse the charge on the newer one. Am now waiting for the newer one. Hope it's good and they reverse charge, and I can give them a good rating. We'll see.
Point is they're no't exactly the same. If one works well, it doesn't matter and you save money. If it doesn't work well ...
When researching these carbs, some don't even have idle mixture screws so watch out for that. Also warranties/returns vary widely, so you might want to consider that too.