Engine starting/running problems

[Iltetp]

I have a B&S 17.5 hp engine, M/N 31C707-3346-G6, on my Craftsman riding mower.
I bought the mower used and when i started it it would run wide open on high or low throttles. I could not get it to slow down so i replaced the carb with a after market Nikki Carb, had after market carb when i bought it, as well as the gas line, spark plug, coil, fuel filter, air filter and gasket. Now it won't start unless i place and hold my hand over the intake tube. It will start but dies immediately, other wise it will not start. Are there any suggestions?

 

[Scrubcadet10]

Sounds like a faulty Chineseium carburetor to me.. it's running too lean and when you place your hand over the intake that simulates choking it making the air/fuel mixture richer (less air).
is there any adjustment screw on it? usually on the front left side of the carb, either a flat head screw or it has a limiter cap on it.Or it may have no screw at all.
OEM carb # is 594593.
and the first issue with the throttle staying WOT, probably a governor issue, either it needs adjusted, or it's broken inside the engine
i couldn't find a specific video on that engine but Taryl explains it pretty well in this video, someone else can probably give you specifics for your engine.
skip to 3:00,