Help please! Honda GV 160 lawn mower runs for only for a few seconds

1st time tinkering with a lawn mower or any machine, non-technical. I received an old lawn mower that's been sitting around for a couple of years but used to run perfectly, did not start as is. I sprayed it with starter fluid, ran for only a few seconds good and strong before dying out. Poured some fresh gas behind air filter into carb bowl, same thing, dies after a few seconds. Drained tank and fuel, cleaned carb, fresh fuel same thing. Fuel shutoff valve open. Bought a new carb, same thing, only runs for a few seconds with starter fluid or gas poured into carb bowl. No matter what, always runs strong and good for a few seconds, then engine cuts out like the safety lever released, abruptly.

I need to buy a spark plug socket and sparkplug if that could be problem, so before I make any more purchases, or tear into anything further, any guesses on what culprit might be?

Does it have a fuel shutoff?, most Honda's do, is it open?

Yes, shutoff valve is open.

I see you replaced the carb, which I was going to suggest. When you replaced it, did you get new gaskets, especially the two where the carb mounts to the block. Second did you install them correctly, one has a hole which must match with the passageway on the block side of the carb.

Yes, thank you, all gaskets are fine.

I am not sure what did it, or combination, but running fine now. 1st I changed the spark plug (for some reason cannot upload pic) tip all black, bottom of threads oily, but ran for only a second with starter fluid, later with more gas inserted into bowl. 2nd, gapped the plug, was too tight. Right after that, tipped mower over, got out every drop, filled tank, fired right up! Mowed the lawn with no issues, running like I can imagine new.

I guess a waste to buy new carb, but a good experience and learned a lot.

Thank you all for your help!!!