If you haven't fully cleaned the fuel tank and line plus installed brand new fresh fuel- do that now. If you noted debris- you may have to drop the bowl of the new carb and clean the bowl and main jet (in the bowl nut.)An occasional cough can be caused a valve that sticks intermittently. I will spray through the carb venturi while it is running with carb cleaner to remove any gunk an the stem and followed w/ something like Marvel oil in the same fashion. A bit of Seafoam may do the trick as well.

Starting with fresh gas, run Sta-Bil in your fuel all the time. Put it in the gas can before filling it.

I don't know why you installed a new carb you should have cleaned the jets and you would have had a great running mower.

Qustion: Did you replace it with a bran new carb or a rebuilt one. You must make sure the carb you added has the same size jets sounds to me it's running to rich. remove the spark plug and see if it is all black if so you are running very rich with the wrong jets.

I had a hell of a time on a techumsey engine with the engine farting every few minutes the solution was reducing the carb main jet from 75 to 65 and it works like new.

I installed a brand new one because I'm a female who didn't know where a carb was on a mower a week ago. We figured it would be easier than me trying to get the old one back together correctly.

It looks like exactly the same part and I got the part number from the manufacturer of the mower.

There's a small screw on the side of the carb and I turned it a tiny bit this morning and the mower is now running great.

Glad you got it working, Happy Mowing